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Human activities have significantly accelerated emissions of each carbon dioxide and biologically reactive nitrogen into the atmosphere. As nitrogen availability frequently limits forest productivity, it has long been anticipated that anthropogenic nitrogen deposition ought to stimulate carbon sequestration in forests. The present study aimed to understand the effects of nitrogen addition on the growth of the Syzygium cumini in ambient (408 ppm) and elevated (450 ppm, 500 ppm, 550 ppm and 600 ppm) carbon dioxide conditions. The addition of nitrogen in the form of potassium nitrate in different levels (0, 3, 6, 12, & 24 g N m−2) was used in this study. The responses of the plant in terms of growth (shoot length, leaf length and leaf width) were examined. Multiple regression equation was used for the model fit to determine the carbon content. The carbon content was found to be higher in all ambient and elevated CO2 conditions at the nitrogen addition level of 24 g N m−2.

As in vitro culture environments can be mutagenic, it's challenging to produce true-to-true type plants from meristems. Therefore, the present study aimed to devlop an efficient protocol for micropropagation from shoot tip explants of medicinally important Aloe vera using different concentrations of A. vera leaf gel (AvG) as organic supplement to the culture media. Assessment of the genetic stability of A. vera in vitro multiplied plants compared to the donor plant is one of the most important pre-requisites especially before its use for commercial and medicinal purposes. For shoot multiplication, the highest number of axillary shoots recorded was 13.27 ±5.11 with an average length of 2.21 ±0.84 cm on M3 medium (MS + 0.2 mg L−1 of β-indole butyric acid (IBA) + 3 mg L−1 benzylamino-purine (BA) + 5% AvG). All three strength of MS medium (1, 1/2, 1/4) with different concentrations of AvG resulted in 100% root induction after 4 weeks of culture. All the rooted microshoots (100%) were successfully acclimatized. To provide a reliable conclusion on its nutritive supply to MS medium, the total phenolic (TPC), condensed tannins (TTC), flavonoid (TFC), and flavonol (TFlC) content as well as the antioxydant activity of AvG were investigated. TPC and TTC values were found to be 31.02 ± 0.46 μg gallic acid equivalent mg−1 of extract and 4.00 ± 0.96 μg catechin equivalent mg−1 of extract, respectively while TFC and TFlC were 13.58 ± 0.84 and 9.75 ± 0.58 μg rutin equivalent mg−1 of extract, respectively. The results of antioxydant activity of AvG following DPPH, FRAP and ABTS assays were equal to 12.50 ± 0.89; 49.59 ± 2.07 and 64.93 ± 3.23 µmol Trolox equivalent mg−1 of extract, respectively which may explain the positive role of AvG as supplement. The genetic stability of in vitro propagated A. vera plants was evaluated using 10 inter simple sequence repeat (ISSR), 10 start codon targeted (SCoT) and 10 simple sequence repeat (SSR) markers. Out of these, 5 ISSR, 3 SCoT and 6 SSR primers produced resolvable, reproducible and scorable bands. ISSR primers generated 32 amplification products ranging from 200 to 1040 bp in size with a mean number of 6.4 bands while SCoT primers generated 33 amplicons with an average of 11 bands in the range of 160–2410 bp. In the SSR products, 6 bands were observed, each primer produced one band ranging from 410 to 720 bp. All banding profiles were monomorphic proving that the stability of the micropropagated A. vera plants was maintained. This study proved the suitability of supplementing in vitro culture media with AvG to enhance direct regeneration through shoot tip explants of A. vera for large scale micropropagation applications.

Dodder is a parasitic weed that causes a lot of damage to citrus production in the south of Kerman province, Iran. Introducing cultivars which tolerant to this parasite can be considered a very effective step in controlling it. Therefore, to evaluate the tolerance of seven important citrus species to dodder, an experiment was conducted in a randomized complete block design with three replicates in greenhouse conditions for two years (2016-2017). In this experiment, the reaction of orange, local, and Kara tangerine, grapefruit, Valencia orange, local orange, and lemon seedlings to dodder infestation was investigated. The infestation was done artificially by placing 10 dodder’s thallus on the seedlings of each of the mentioned species. After the successful establishment of the parasite (during 4 months), chlorophyll content, number of stems on citrus species shoots, number of capsules in infested seedlings, and seed weight on each seedling were measured and recorded. The results of this study revealed that different species of citrus showed very different reactions to the presence of dodder so that these species can be based on the success rate of its attachment to them into tolerant and sensitive species. According to the results, Valencia oranges and Bitter orange were tolerant to dodder, but lemon and tangerines (local and Kara) showed high sensitivity. A cross-sectional of plant tissues showed that concerning anatomic view, there was no difference in haustorium penetration between the different citrus species. As a result, it is recommended to use physiological, genetical, and biochemical analysis to distinguish the differences.

Pennisetum pedicellatum Trin. is a C4 tropical perennial forage grass known as Deenanath grass holding great potential to address vital, puzzling issues such as bio-economy, human health and the environment. Genetic complexity not only is a big barrier in selection and breeding practices but also restricts harnessing of the full potential of this multipurpose fodder crop. By optimizing a rapid, effective and consistent in vitro regeneration protocol through callus mediated and direct shoot organogenesis, we can multiply these plants for producing a large amount of biomass. Calli were induced from mature seeds and shoot apices of two genotypes on Murashige and Skoog (MS) medium containing different levels of 9.0–22.5 µM 2,4-Dichlorophenoxyacetic acid (2,4-D) and a constant level of 2.22 µM N6-benzyladenine (BA). Seventy-one percent of the calli turned embryogenic when 2,4-D (2.25 µM) was reduced in the medium. Somatic embryogenesis was accomplished on MS medium with an increased level of either BA (4.4–17.6 µM) or kinetin (4.6–18.4 µM) along with 0.56 µM 2,4-D. Ultra-structural and histological studies indicated globular, scutellar and coleoptilar somatic embryos. A maximum of 82.7±1.6% plant regeneration was accomplished from seed explants on MS medium containing 8.8 µM BA and 0.56 µM 2,4-D. Multiple shoots were induced on MS media containing either BA (4.4–18.0 µM) or kinetin (4.6–18.4 µM) along with 0.56 µM 2,4-D using shoot apices. A maximum of 22.1±0.45 shoots per shoot apex was produced on MS medium containing 8.8 µM BA and 0.56 µM 2,4-D. Successful rooting of healthy shoots generated through both the pathways could be optimized on ½MS medium containing 0.4% charcoal. Complete plants could be hardened in plastic pots and were well established on field conditions. In vitro regeneration was established for the first time successfully, which would be very useful for genetic improvement of this apomictic species through transgenic approach.

A number of studies have focused on the effects of rare earth elements (REEs) on crop plants, while little attention has been paid on how tolerant plant species respond to increasing mixed REE concentrations. In this study, ramie (Boehmeria nivea L.) was exposed to a series of REE concentrations prepared with equimolar mixtures of 16 REEs (i.e. 0, 1.6, 8, 16, 80, 160, 400, 800 μmol/L) in order to explore REE accumulation and fractionation characteristics in ramie and the responses of this plant to mixed REEs. Results show that ramie root and shoot biomasses are unaffected under lower REE concentrations (1.6–80 μmol/L), while the growth of ramie and the uptake of nutrients especially Ca and Mn are largely inhibited under higher REE concentrations (160–800 μmol/L). The P and Mo concentrations in the roots increase with the increasing REE concentrations in the solution, suggestive of an involvement of P and Mo in dealing with the high concentrations of REEs in this plant. The preferential uptake of Ce and heavy REEs (HREEs) and the preferential transport of HREEs within the plant lead to a positive Ce anomaly and a HREE enrichment in ramie leaves. Our study suggests that ramie could be a good candidate for the phytoremediation of heavily REE-contaminated soils (e.g., REE mine tailings in southern China). Our results also shed light on points of taking into account phytoremediation management strategies of REE-contaminated soils (e.g., P and Mo fertilization).

Crop infestation species have acquired resistance to herbicides, stimulating the search for new control methods. Plants secondary metabolites can hold more sustainable alternatives, as they can be used for development of natural herbicides. This study evaluated phytotoxic effects of aqueous extracts of Ilex paraguariensis leaves on Conyza bonariensis, an infesting species of Brazilian crops. Different concentrations of decoction and infusion extracts were tested in germination and growth bioassays. Adult plants were evaluated for leaf anatomy effects caused by the yerba mate extract. HPLC analysis was used to quantify the three major chemical constituents. The most effective aqueous extract (decoction 1.0%) decreased the percentage of seed germination, germination speed index, and percentage of germination-derived seedling formation, and increased the time for seedling formation. Shoot and root growth were not affected by this extract. In adult plants, the same extract damaged epidermis and palisade/lacunous parenchyma six hours after exposure. Caffeine was found as the major compound of this extract, followed by rutin and quercetin. Therefore, aqueous extract by decoction 1.0 % of I. paraguariensis leaves showed potential for control of C. bonariensis infestation and rather promising for the development of a natural herbicide.

Turmeric (Curcuma longa L.) is of great importance due to its medicinal properties and industrial uses. However, as in most plants, physiological and biochemical changes occur in turmeric plants subjected to saline conditions. This study aimed to evaluate the growth and antioxidant response of turmeric plants, and the yield and composition of turmeric essential oil under saline stress. The study was greenhouse-based, and 180 days old turmeric plants were treated with 50, 100, and 150 mM NaCl solutions for 130 days. Plants grown under high NaCl concentrations showed significantly reduced shoot length and shoot and rhizome biomass accumulation. Large amounts of proline accumulated in the leaves at 150 mM NaCl. Lipid peroxidation and malondialdehyde content increased with salinity in both leaves and rhizomes. Antioxidant enzymes showed greater activity in the leaves of plants exposed to high NaCl concentrations. Salinity altered the yield and chemical composition of the essential oil in the rhizomes. A total of 114 compounds were identified in the essential oil, with the main compounds from the sesquiterpenes class. Sesquiterpenes can constitute a secondary antioxidant system which can assist the primary antioxidant defense system to maintain the levels of hydrogen peroxide in cells at concentrations sub-lethal to turmeric plants. In addition, the presence of rhizomes has a mitigating effect on salt stress in this species due to the antioxidant activity of the essential oil present in the rhizomes.

In this study, to evaluate the effect of isolates of different species of Trichoderma on some morphological traits of canola and to obtain suitable antagonist isolates for biological control of canola crown rot disease, the effect of 71 Trichoderma isolates on Sclerotinia sclerotiorum was investigated in the laboratory by volatile compound and non-volatile metabolite methods. In the volatile metabolite assay, the isolate ARCTr281 (T. harzianum) was more efficient than the other isolates with a 20% reduction in hyphae density and non-formation of S. sclerotiorum sclerotia. In the non-volatile metabolite assay, ARCTr272 (T. harzianum) with 73.7 and 62.22 at 25 and 15% concentrations and T. viride isolate ARCTr432 (20.37%) at 5% concentration were successful in inhibiting S. sclerotiorum mycelia growth. Six superior isolates were selected for greenhouse studies. Using two-stage Trichoderma isolates in the greenhouse, height, fresh and dry weight of shoots and roots, number of pods, pod length, pod diameter and number of seeds per pod in the presence of pathogen all increased. The results of principal component analysis showed that the first two components accounted for 86% of the total variation among the data. The results showed that for the first component, the traits of total grain weight, pod diameter, branch number, shoot dry weight and fresh weight of root were the most important traits in grouping the isolates. In the trait second component, plant height and number of seeds per pod were important traits. Mean comparisons were performed using an LSD test and showed significant differences between the fungi used in non-volatile metabolite and greenhouse studies. According to the results of this research, the fungal isolates of T. harzianum (ARCTr281, ARCTr272 and ARCTr418) were the most effective antagonists in improving plant traits and controlling canola rot disease in both the laboratory and the greenhouse.

Biogenic volatile organic compounds (VOCs) emitted by plants can reveal information about plant adaptation, defense processes, and biological pathways. Thus, such VOC data may be utilized to capture phenotypic plant responses to the environment. In this study, the main objective was to evaluate the potential of biogenic compounds, including VOCs, to phenotype two pea cultivars, Ariel (susceptible) and Hampton (high levels of partial resistance) for resistance to Aphanomyces root rot disease. Plants were monitored non-destructively for VOC emission at three-time points (15, 20, and 30 days after inoculation, DAI) using dynamic headspace sampling with gas chromatography-flame ionization detection (GC-FID) system, as well as destructively at the end of the experiments, using solvent extraction and pyrolysis of both shoot and root tissues. A non-inoculated control (mock-inoculated with distilled water) was utilized to compare the plant responses within a cultivar. The common chemical peaks between control and inoculated samples of both cultivars (RTcm) were analyzed after normalizing the relative peak intensity of inoculated samples with those of control samples, prior to a comparison between cultivars. In addition, unique chemical peaks (RTuq) present in inoculated samples, but not in control samples were also identified and their relative peak intensities were compared. Among the released green leaf volatiles (RTcm), the normalized relative peak intensity of hexanal emission, at 20 DAI, was higher in Ariel than that of Hampton. In addition, several putative chemical peaks (both RTcm and RTuq), previously known as indicators for disease response, exhibited some differences in their emission rates between pea cultivars in at least one of the time points. The destructive sampling revealed that shoot samples produced more putative unique biomarkers (RTuq) than the root samples. Based on the differences in putative chemical peaks between cultivars, this initial study supports the concept of utilization of biogenic biomarker-based phenotyping in distinguishing levels of resistance in the evaluated pea cultivars. More research is needed to further this approach for phenotyping other plant cultivars. Upon validation, the VOC profile integrated with high-throughput VOC sensing techniques can serve as a novel mechanism for phenotyping disease responses in crops.

Hormones play important roles in vegetative and reproductive processes; however, the regulatory roles of hormones in Nelumbo nucifera (Lotus) growth and development are unclear. In this study, nine types of endogenous hormones, including gibberellins (GA1, GA3, and GA4), indole-3-acetic acid (IAA), brassinolide (BR), ethylene (ETH), jasmonic acid (JA), abscisic acid (ABA), and zeatin (ZT) were detected in dormant shoot tips, vegetative shoot tips, developing leaf buds, and developing flower buds of lotus. The results indicated that GA, ETH, and BR signaling can promote vegetative and reproductive development of lotus. GA signaling regulates plant height and stimulates flower bud differentiation. GA levels were the highest in the flower buds; exogenous GA3+4 increased plant height by approximately 90%, increased flower quantity by nearly 40%, and advanced flowering by 4 d. Suppressing GA biosynthesis using paclobutrazol decreased plant height and flower quantity by 38% and 87.1%, respectively, and delayed flowering by 15.6 d. ETH signaling has positive regulatory effects on vegetative growth and flower development. The ETH concentration in the developing leaf buds was at least 50% higher than that in other samples. Ethephon spraying led to remarkable increases in plant height and leaf thickness and extended the flowering duration. BR signaling acts as a growth promoter during vegetative and reproductive development in lotus. The highest BR levels were detected in the vegetative shoot tips. External application of 28-epihomobrassinolide resulted in growth-promoting phenotypes including longer scapes, thicker leaves, and prolonged flowering.

This study represents an efficient preliminary protocol for in vitro mass production of two Paulownia species (Paulownia hybrid and Paulownia tomentosa) seedlings by using seed explant. Different concentrations of benzyladenine (BA) or Kinetin (Kin) (0.0, 2.0, 4.0, 6.0, 8.0 and 10.0 mg/L) were tested during multiplication stage. The number of shoots/explants was significantly increased with increasing either BA or Kin concentration; however, the shoot length significantly decreased. Data show that media fortified by BA (10 mg/L) combined with indole butyric acid (IBA) at 1.0 or 1.5 mg/L recorded the highest number of shoots/explant (9.13 and 9.25, respectively). After six weeks during the multiplication stage, data cleared that media fortified by benzyladenine (10 mg/L) combined with IBA at 0.5 mg/L recorded the highest shoot length (3.23 cm). The inclusion of indole butyric acid (IBA) or naphthalene acetic acid (NAA) at 1.0–1.5 mg/L to the medium significantly increased the number of roots/plantlets and the highest root length. The results indicated that IBA supplementation was more effective than NAA for in vitro rooting of both Paulownia species. The best treatment for multiplication was 10 mg/L and 8.0–10 mg/L BA for P. hybrid and P. tomentosa, respectively. Peat moss and sand (1:1, v/v) or peat moss and sand (1:2, v/v) were investigated as soil mixture during the adaptation stage. The results referred that Paulownia species plantlets were successfully survived (100 %) in soil mixture contained peat moss: sand (1:2, v/v). This mixture recorded the highest values of plantlet height and number of leaves/plantlets.

Cotton architecture is partly determined by shoot branching and flowering patterns. GhBRC1 was previously identified by RNA-seq analysis of nulliplex-branching and normal-branching cotton. However, the roles of GhBRC1 in cotton remain unclear. In the present study, investigations of nuclear localization and transcriptional activity indicated that GhBRC1 has characteristics typical of transcription factors. Gene expression analysis showed that GhBRC1 was highly expressed in axillary buds but displayed different expression patterns between the two branching types. Overexpression of GhBRC1 in Arabidopsis significantly inhibited the number of branches and promoted flowering. In contrast, silencing GhBRC1 in cotton significantly promoted seedling growth. GhBRC1 was induced by multiple hormones, including strigolactones, which promoted seedling growth and seed germination of Arabidopsis plants overexpressing GhBRC1. Consistent with these findings, RNA-seq analysis of virus-induced gene silencing treated cotton revealed that a large number of genes were differentially expressed between GhBRC1-silenced and control plants, and these genes were significantly enriched in plant hormone signalling pathways. Together, our data indicates that GhBRC1 regulates plant branching and flowering through multiple regulatory pathways, especially those regulating plant hormones, with functions partly differing from those of Arabidopsis BRC1. These results provide insights into the molecular mechanisms controlling plant architecture, which is important for breeding cotton with ideal plant architecture and high yield.

Phosphorous (P) plays the prominent role to promote the plants storage functions and structural roles, as it is recognized as a vital component of ADP, ATP, Cell wall as well as a part of DNA. Soils acts as the sink to supply P to plants because soil pH and its physical condition are the main factor which regulate the solubility and availability P element. Phosphorus is not deficient in Pakistani soils but its availability to plants is the serious matter of concern. A pot experiment was conducted to evaluate P dynamics in two different soil series of Pakistan (Bahawalpur and Lyallpur) using Maize as test crop. The treatments applied were T0: Control (without any fertilizer), T1: Recommended DAP @648 mg pot−1, T2: Half dose DAP @324 mg pot−1, T3: Recommended rate of TSP @900 mg pot−1, T4: Half dose TSP @450 mg pot−1. Soil analysis showed that Bahawalpur soil has sandy clay loam texture with 33% clay and Lyallpur series has sandy loam texture with 15.5% clay; furthermore, these soil contain 4.6 and 2.12% CaCO3 respectively. Results showed an increase in P concentration in roots (23 mg kg−1) with the application of half dose of TSP in Lyallpur series and lowest in Bahawalpur series (14.6 mg kg−1) at recommended dose of DAP. Concentration of P in shoots responded the same; increase at half dose of TSP (16.7 mg kg−1) and lowest at full dose of DAP in Bahawalpur series as (15.58 mg kg−1). Adsorbed P (17 mg kg−1) was recorded highest in Bahawalpur soil with more clay amount in pot with DAP application but lower in Lyallpur soil series (14 mg kg−1) with the application of applied TSP. The PUE was recorded highest in Lyallpur series with the application of half dose of TSP and it was 61% more than control and was Highest in Bahawalpur series was with the application of recommended dose of DAP is 72% more than control treatment. On estimation; results showed that applied sources made an increase in P availability than control, but TSP gave better P uptake than DAP unless of rates applied. Soil of Lyallpur series showed better uptake of P and response to applied fertilizers than Bahawalpur series which showed more adsorption of P by high clay and CaCO3 amount. Conclusively, the study suggested that soil series play a crucial role in choosing fertilizer source for field application.

Microbial resistance and other emerging health risk problems related to the side effects of synthetic drugs are the major factors that result in the research regarding natural products. Fruits, leaves, seeds, and oils-based phyto-constituents are the most important source of pharmaceutical products. Plant extract chemistry depends largely on species, plant components, solvent utilized, and extraction technique. This study was aimed to compare the ethanolic extracts of a mangrove plant, i.e., Avicennia marina (1E: Lower half of A. marina‘s pneumatophores, 2E: A. marina‘s leaves, 3E: Upper half of A. marina‘s pneumatophores, and 4E: A. marina‘s shoots), with non-mangrove plants, i.e., Phragmites australis (5E: P. australis‘s shoot), and Moringa oleifera (6E: M. oleifera‘s leaves) for their antimicrobial activities, total phenolic contents, antioxidant activity, and cytotoxicity potential. The antimicrobial activity assays were performed on gram-positive bacteria (i.e., Bacillus subtilis and Staphylococcus aureus), gram-negative bacteria (i.e., Escherichia coli, and Pseudomonas aeruginosa), and fungi (i.e., Aspergillus niger, Candida albicans, and Rhizopus spp.). We estimated antioxidant activity by TAC, DPPH, and FRAP assays, and the cytotoxicity was evaluated by MTT assay. The results of antimicrobial activities revealed that B. subtilis was the most sensitive to the tested plant extracts compared to S. aureus, while it only showed sensitivity to 6E and Imipenem. 5E and 6E showed statistically similar results against P. aeruginosa as compared to Ceftazidime. E. coli was the most resistant bacteria against tested plant extracts. Among the tested plant extracts, maximum inhibition activity was observed by 6E against A. niger (22 ± 0.57 mm), which was statistically similar to the response of 6E against C. albicans and 3E against Rhizopus spp. 2E did not show any activity against tested fungi. We found that 6E (208.54 ± 1.92 mg g−1) contains maximum phenolic contents followed by 1E (159.42 ± 3.22 mg g−1), 5E (131.08 ± 3.10 mg g−1), 4E (i.e., 72.41 ± 2.96 mg g−1), 3E (67.41 ± 1.68 mg g−1), and 2E (48.72 ± 1.71 mg g−1). The results depict a significant positive correlation between the phenolic contents and the antioxidant activities. As a result, phenolic content may be a natural antioxidant source.

The present study investigates ameliorative effect of silicon nanoparticles (SiNPs) and indole acetic acid (IAA) alone and in combination against hexavalent chromium (CrVI) toxicity in rice seedlings. The results of the study revealed protective effects of SiNPs and IAA against CrVI toxicity. The 100μM of CrVI imposed toxic effects in rice seedlings at morphological, physiological and biochemical levels which coincided with increased level of intracellular CrVI and declined level of endogenous nitric oxide (NO). The CrVI enhanced levels of superoxide radicals (SOR) (59.51% and 50.1% in shoot and root, respectively) and H2O2 (19.5% and 23.69% in shoot and root, respectively). However, when SiNPs and IAA were applied to plants under CrVI stress, they enhanced tolerance and defence mechanisms as manifested in terms of increased biomass, endogenous NO, photosynthetic pigments, and antioxidants level (ascorbate-glutathione cycle). It was also noticed that CrVI arrested cell cycle at G2/M phase whereas growth was restored as compared to control when SiNPs and IAA were supplemented. Thus, the hypothesis that combined application of SiNPs and IAA will be effective in alleviating CrVI toxicity is validated from the results of this study. Moreover, in SiNPs and IAA-mediated mitigation of CrVI toxicity, endogenous NO has a positive role. The importance of the study will be that the combination of SiNPs and IAA can be utilized against heavy metal stress and even when supplied alone, they will enhance the crop productivity parameters with and without stress conditions.

Orchids are one of the most fascinating plant families amongst the flowering plants. Amongst the various orchid genus Cymbidiums figure out prominently. The present study focuses on the development of an efficient in vitro regeneration protocol for Cymbidium aloifolium, an epiphytic orchid with high commercial value. It also aims at analysing the important phytochemicals and antioxidant potential of in vitro and in vivo plants. The effects of MS basal media (half or full strength) and MS medium supplemented with BAP were studied for in vitro seed germination. Among different media, 1/2 MS medium resulted in in vitro seed germination, protocorm development and plantlets formation in the shortest duration. However, 6-Benzylaminopurine (BAP) played an important role during proliferation of protocorms or in vitro multiplication, thus resulted in maximum number of shoots (39), root length (6.10 cm) on MS medium with 1.0 mg/L BAP. Largest shoot length was observed on solid BM-2 medium. 90% of the plantlets survived in the potting mixture consisting of cocopeat, perlite and wood saw dust in a ratio of 1:1:1. Comparative phytochemical analysis revealed that in vitro regenerated plants showed a higher yield of secondary metabolites. This work will facilitate the utilization of orchid phyto-constituents for various pharmaceutical applications in the industries.

This study was designed to evaluate the response of rainfed lentil to manganese (Mn) foliar application in high-calcareous soil located in the arid Mediterranean area. Field experiments on two clay calcareous soils containing different free carbonates and exchangeable Mn contents were carried out. The soil“1” has Mn content (DTPA extraction) of 7.5 mg kg−1 and it contains 8.9% of free carbonates. The soil“2” contains 3.3 mg kg−1 of Mn and it has a free carbonates level of 15.9%. Five foliar spray concentrations of Mn in lentil (0 as control; 0.5%; 1%; 3%; and 8%) were tested. Mn was applied in the sulfate form at flower bud and flowering. The soil“1” and soil”2” were evaluated during the 2016–17 and 2017–18 seasons, respectively. Results showed that foliar Mn feeding did not enhance grain yield and its components. Mn foliar spray over than 1% resulted in leaf damage during the rainfall season 2017–18 (429 mm) compared to 2016–17 (289 mm). At 8% of Mn, the phytotoxicity reduced grain yield by 34.5% compared to control. For both calcareous soils, shoot Mn content at the end of flowering was over 30 mg kg−1 for control and exceeded 1800 mg kg−1 at 8% of Mn. No antagonism or synergy between Mn and the other nutrients (N, P, K, Ca, Mg, Cu, and Zn) was recorded.

In eco-system population several heavy metals play important roles those are spread from the domestic and industrial wastes, causing huge crop damage by damaging plant tissues. The collected heavy metal tolerance bacterial samples from agricultural lands of Durgapur zone, West Bengal, India against Molybdenum, Lead, Cobalt and Zinc are observed as Proteus sp. Klebsiella sp. and Bacillus sp. Pseudomonas sp. and Staphylococcus sp. as predominant. Demonstrated some confines displayed high protection from heavy metals with at least Minimum Inhibitory Concentration (MIC) for weighty metals as 80 µg/ml for Molybdenum, 160 µg/ml for Lead, 140 µg/ml for Cobalt and 1200 µg/ml for Zinc. In this study we noticed a relationship between substantial metal opposition and anti-microbial resistance in bacterial samples. The heavy metal free samples of Triticum aestivam showed batter results in root length and shoot length than the heavy metal contaminated samples.

This research paper aims to characterize and evaluate the morphological as well as the physical properties of Ethiopian Y. Alpina bamboo based on the effect of age and height. The bamboo has been harvested in the Amhara region in the Injibara town in January 2020. Nine bamboo samples have collected at the age of 1, 2, and 3 years old. Bamboo Culm has been divided into three positions along with Culm height like bottom, middle, and top. Analysis of the significance of age and height on physical properties has been done using Stata.12 software with linear regression and ANCOVA. Both morphology and physical properties have been used to improve understanding of bamboo’s performance used as a structural application, bamboo composite processing, fiber extraction process, bamboo laminated processing, and furniture making materials. Age of 1-year-old bamboo has high Culm diameter, wall thickness, Internode length compared to the age of 2 and 3 years old bamboo. When bamboo generates new shoots under the rhizome, new shoots generate and grow high morphological properties of bamboo compared to the previous old bamboo. Percentage of moisture content, shrinkage in wall thickness, and shrinkage in Culm diameter decrease when the age of bamboo increases. Furthermore, these properties have been decreased along with Culm height from bottom to the top position. Oven–dry density increase with the age of bamboo increase, whereas its property has been decreased along with Culm height from bottom to the top position. Cellulose content increase when the ages of Culm older, however, extractive and ash content decrease when the ages of Culm older. From the greatest to lowest of hemicelluloses, and lignin contents are at the ages of 2, 3, and 1 year–old respectively.

Frequent flooding and waterlogging adversely impair maize production in China mainly; maize seedlings are extremely sensitive to waterlogging stress at early growth stages. Therefore, improving the resistance of maize seedlings under waterlogging stress is essential for maize production. This study investigated the effects of exogenous spermidine (Spd) and brassinolide (BRs) application on maize seedling adaptation to severe waterlogging. Maize cultivar Xingken-6 (XK-6) was used and treated with Spd (1.5 mg L−1) and BRs (1.0 mmol L−1) under 14-days waterlogging treatments at three-leaf (V3) and fifth-leaf (V5) stages. We found that waterlogging stress decreased overall maize seedling growth by increasing oxidative damage due to reactive oxygen species (ROS) accumulation, decreased photosynthetic capacity, chlorophyll concentration, and significantly damaged chloroplast structure and root anatomy. Spd and BRs treatments effectively relieved impairment of waterlogging by increasing root dry matter (DM), shoot DM, root length, root volume, number of living cortical cells in seminal roots, and net photosynthetic rate. On the other hand, Spd and BRs decreased root aerenchyma area and ROS production across growth stages. Our results demonstrated that Spd and BRs enhanced maize seedling tolerance to waterlogging stress by simultaneously regulating root anatomical structures, photosynthetic machinery, and antioxidant defense systems.

Cenchrus ciliaris is a potential forage grass that is widely distributed in saline desert condition across Africa, Australia and Asia. To examine anatomical characteristics relating to ionic and nutritional contents in response to salinity, Cenchrus ciliaris populations from the naturally salt-affected region of the Cholistan Desert, Pakistan were collected. The experiment was planned in a completely randomized design (CRD) with four replications and four treatment levels (0, 100, 200, and 300 mM NaCl) in a hydroponic system. After six months of growth in nutrient solution anatomical characteristics relating to ionic and nutritional traits were studied. It was hypothesized that C. ciliaris at higher salt stress must have developed some specific structural adaptations, which are responsible for better survival under high salt stress. At root level, C. ciliaris showed decreased root thickness with greater proportion of parenchyma cells in cortical region and increased sclerification in cortex and pith regions at high salinity levels, which are vital for water conservation under osmotic stress. At stem level increased stem area, cortical and vascular bundle cell area were recorded with increase in salinity level of external growth medium. Salt tolerance in C. ciliaris mainly associated with restricted uptake of toxic Na+ and Cl− ions at roots, accompanied by increased concentration of K+ and Ca++ in shoot. Under high salinities, C. ciliaris showed increased epidermis thickness, well developed bulliform cells, and increased trichome density at leaf level. All these structural modification in this species may contribute towards water conservations under physiological stress that is caused by high level of soil salinity. Various nutritional traits such as crude protein, ash content, relative feed value, and net energy of lactation slightly improved with salinity. Present study revealed nutritional potential, ionic contents and anatomical adaptations of C. ciliaris to cope with salinity. As such this species can be used to produce valuable fodder under saline desert environment.

International audience; Arid/semi-arid and coastal agricultural areas of the world are especially vulnerable to climate change-driven soil salinity. Salinity tolerance in plants is a complex trait, with salinity negatively affecting crop yield. Plants adopt a range of mechanisms to combat salinity, with many transporter genes being implicated in Na+-partitioning processes. Within these, the high-affinity K+ (HKT) family of transporters play a critical role in K+ and Na+ homeostasis in plants. Among HKT transporters, Type I transporters are Na+-specific. While Arabidopsis has only one Na + -specific HKT (AtHKT1;1), cereal crops have a multiplicity of Type I and II HKT transporters. AtHKT1; 1 (Arabidopsis thaliana) and HKT1; 5 (cereal crops) ‘exclude’ Na+ from the xylem into xylem parenchyma in the root, reducing shoot Na+ and hence, confer sodium tolerance. However, more recent data from Arabidopsis and crop species show that AtHKT1;1/HKT1;5 alleles have a strong genetic association with ‘shoot sodium accumulation’ and concomitant salt tolerance. The review tries to resolve these two seemingly contradictory effects of AtHKT1;1/HKT1;5 operation (shoot exclusion vs shoot accumulation), both conferring salinity tolerance and suggests that contrasting phenotypes are attributable to either hyper-functional or weak AtHKT1;1/HKT1;5 alleles/ haplotypes and are under strong selection by soil salinity levels. It also suggests that opposite balancing mechanisms involving xylem ion loading in these contrasting phenotypes exist that require transporters such as SOS1 and CCC. While HKT1; 5 is a crucial but not sole determinant of salinity tolerance, investigation of the adaptive benefit(s) conferred by naturally occurring intermediate HKT1;5 alleles will be important under a climate change scenario.

Brassinosteroids (BRs) are the sixth important plant hormones that induce their effect at micro-level concentration. The importance of its analogous under in vitro condition for many studies includes the study of response in plants aimed at improving various developmental, physiological, morphological, biochemical processes without the involvement of climatic factors, nutrients and diseases. BR improves and increases regeneration and multiplication rate by induction of callus growth, somatic embryos, tracheary elements, shoot elongation, formation of 2embryogenic tissue, stimulation of branch elongation, etc. These provide rapid disease-free clonal propagation of improved varieties within less time and space. BRs improve photosynthetic processes, antioxidant enzymes activities, synthetic seed production and elicitation of secondary metabolites production. Most importantly, it provides resistance from abiotic stresses, for example, oxidative and salinity stress. This review summarizes role of brassinosteroid and its various analogs in improving different morphological, physiological and biochemical attributes in various crop plants grown in vitro, both under normal as well as abiotic stress conditions.

Cadmium (Cd) contamination in paddy soils means that the rice produced there may be unsafe for human consumption. A hydroponic study was conducted to enrich rice seedlings with zinc (Zn) or manganese (Mn), and the uptake and transport characteristics of Cd in these Zn- and Mn-rich seedlings were subsequently investigated using a greenhouse pot trial. The results showed that hydroponic cultivation in 10–50 µmol L–1 Zn (ZnSO4·7H2O) or 50–250 µmol L–1 Mn (MnSO4·H2O) for 30 d had no significant impact on rice growth, while the accumulation of Zn and Mn was 7.31–18.5 and 25.4–47.7 times higher, respectively, than in the control (no Zn or Mn addition). The accumulation of Cd in the Zn- and Mn-rich rice plants was 26.3%–38.6% and 34.4%–44.5% lower than that in the control, respectively, and the translocation factors of Cd from roots to shoots also decreased by 23.3%–41.3% and 25.3%–37.0%, respectively, after transplanting to Cd-contaminated soils. Furthermore, the relative expression levels of OsIRT1 (Oryza sativa iron-regulated transporter 1) were downregulated by 40.1%–59.3% and 16.0%–25.9%, respectively, in the Zn- and Mn-rich seedling roots. This downregulation may indicate a possible mechanism contributing to the reductions in Cd absorption. Field experiments confirmed that the Zn- and Mn-rich seedlings produced brown rice (unpolished rice grains) with significantly decreased concentrations of Cd (34.2%–44.4%). This study provides an innovative method for reducing the food safety risks from rice grown on slightly to moderately Cd-contaminated paddy soils.

Tissue culture methods are useful in assessing the tolerance of various stresses due to the ease of controlling stress under in vitro conditions. This study aimed to investigate the response of sugarcane genotyps to drought stress using calli as a model system. For inducing sugarcane callus, the medium of Murashige and Skoog (MS) was used with different mannitol concentrations (100, 200, and 300 mM) to measure their effects on callus frequency, the day of callus initiation, embryogenic potential, relative growth rate (RGR), water and proline contents, K+ and Na+ contents, as well as the formation of shoot and roots for three sugarcane genotypes (e.g., GT 54-9, G 84-47, and pH 8013). The RAPD-PCR analysis was carried out using five oligonucleotide primers to identify the genetic variation among sugarcane genotypes. The results indicated that the degree of callus proliferation varied from 70 − 86%. The highest value of callus proliferation, PGR, shoot formation was recorded for the genotype GT 54-9 compared to the other two genotypes (G 84-47 and pH 8013). Calli treated with 100 mM mannitol showed the highest RGR, proline and waer contents for the genotype GT 54-9, while, those treated with 300 mM recorded the lowest values of these parameters for the genotype pH 8013. The genotype G 84-47 collected highest Na+ content, while the genotype pH 8013 collected highest K+ content. The results of this study recommend preference for GT 54-9 genotype, which is considered the most promising genotype, showing more tolerance to drought stress based on all studied traits.

Increasing zinc (Zn) concentration in wheat grain is important to minimize human dietary Zn deficiency. This study aimed to investigate the effect of foliar Zn and soil nitrogen (N) applications on the accumulation and distribution of N and Zn in grain pearling fractions, N remobilization, and the relationships between nutrient concentration in the vegetative tissues and grain or its fractions in two cropping years in the North China Plain. The results showed a progressive decrease in N and Zn concentrations from the outer to the inner parts of grain, with most of the accumulation in the core endosperm. Foliar Zn application significantly increased N concentration in the pericarp, and soil N application increased N concentration in each grain fraction. Both treatments significantly increased core endosperm Zn concentration. Foliar Zn had no effect on grain N and Zn distribution. Soil N application made N concentrated in the aleurone, promoted Zn translocation to the core endosperm and also increased N remobilization and its efficiency from the shoot to the grain, but no improved contribution to grain was found. N concentration in grain and its fractions were positively correlated with N in vegetative organs at anthesis and maturity, while positive correlations were obtained between N concentration in the pericarp and progressive central area of the endosperm and Zn concentration in the core endosperm. Thus, foliar Zn and soil N applications effectively increased yield and N and Zn concentrations in the wheat grain, particularly in the endosperm, and could be promising strategies to address Zn deficiency.

Paddy fields contaminated with cadmium (Cd) present decreased grain yield and produce Cd-contaminated grains. Screening for low-Cd-accumulating cultivars is a useful method to reduce the amount of Cd in the grains. The present study aimed to examine the roles of the root morphology and anatomy in Cd translocation and accumulation in rice plants. Twenty-two rice cultivars were used in the first experiment, after which two cultivars [Zixiangnuo (ZXN) and Jinyou T36 (JYT36)] were selected and used in subsequent experiments under hydroponic conditions. The results showed that there were significant differences in Cd concentrations in the shoots (ranging from 4 to 100 mg/kg) and the Cd translocation rates (shoot/root) (from 7% to 102%) among the 22 cultivars, and the shoot Cd concentration was significantly correlated with the Cd translocation rate of the 22 cultivars under 0.1 mg/L Cd treatment. Compared with cultivar ZXN, JYT36 had greater root Cd uptake and accumulation but lower shoot Cd accumulation and Cd translocation rate. The number of root tips per surface area of cultivar ZXN was greater than that of JYT36, while the average root diameter was lower than that of JYT36. Compared with ZXN, JYT36 had stronger apoplastic barriers, and the Casparian bands and suberin lamellae in the root endodermis and exodermis were closer to the root apex in both the control and Cd treatments, especially for suberin lamellae in the root exodermis with Cd treatments, with a difference of 25 mm. The results also showed that, compared with ZXN, JYT36 had greater percentages of Cd bound in cell walls and intracellular Cd but lower Cd concentrations in the apoplastic fluid under the Cd treatment. The results suggested that Cd translocation, rather than root Cd uptake, is a key process that determines Cd accumulation in the rice shoots. The root morphological and anatomical characteristics evidently affect Cd accumulation in the shoots by inhibiting Cd translocation, especially via the apoplastic pathway. It was possible to pre-screen low-Cd-accumulating rice cultivars on the basis of their root morphology, anatomical characteristics and Cd translocation rate at the seedling stage.

Arsenic (As) and cadmium (Cd) belong to the group of major pollutants extremely toxic to plants. Metal hyperaccumulating plants play an important role in phytoextraction of heavy metals. Silicon (Si) plays an important role in the amelioration of heavy metal stress through physio-biochemical mechanisms, which remain poorly understood in hyperaccumulators. The main purpose of this study was to determine the impact of Si on growth and performance of As hyperaccumulator Isatis cappadocica Desv., exposed to As and Cd. Results showed that Si (especially at 1 mM level) alleviated the harmful impact of As/Cd and significantly increased the root and shoot biomass, root and shoot length and chlorophyll contents of I. cappadocica by enhancing the plant defense mechanisms. Between the two investigated harmful elements, As was accumulated in plant parts significantly more than Cd, however with considerably lower toxic growth effects. The As/Cd concentration, bioaccumulation and translocation factor and total As content both in roots and shoots of Si-supplied plant were significantly reduced as a protective mechanism, especially in Cd exposed plant. In comparison with single As/Cd treatment, Si supply reduced H2O2 content, increased total soluble protein content and enhanced glutathione S-transferase activity in shoots. The results of this study clearly showed that Si minimized As/Cd uptake and root to shoot translocation, and therefore Si cannot enhance the phytoextraction potential of this plant species. Additionally, Si-improved growth and reduced oxidative damages caused by excess of As and Cd suggested that the similar mechanisms of metal(loid) alleviation are adopted in hyperaccumulators as well as non-hyperaccumulating plants.

Chickpea shoot exogenously treated with cytokinin showed stunted phenotype of root, shoot and significantly reduced nodule numbers. Genome-wide identification of LRR-RLKs in chickpea and Medicago resulted in 200 and 371 genes respectively. Gene duplication analysis revealed that LRR-RLKs family expanded through segmental duplications in chickpea and tandem duplications in Medicago. Expression profiling of LRR-RLKs revealed their involvement in cytokinin signaling and plant organ development. Overexpression of KLAVIER ortholog of chickpea, Ca_LRR-RLK147, in roots revealed its localization in the membrane but showed no effect on root nodulation despite increased cle peptide levels. Two findings (i) drastic effect on nodule number by exogenous cytokinin treatment to only shoot and restoration to normal nodulation by treatment to both root and shoot tissue and (ii) no effect on nodule number by overexpression of Ca_LRR-RLK147 establishes the fact that despite presence of cle peptides in root, the function of Ca_LRR-RLK147 was shoot mediated during AON.

The article presents the studies on the biomass yield, heating value and thermal decomposition process of the shoots of Lavatera thuringiaca L. plants (solid biofuel) of different age (one to three years old) grown from He–Ne laser stimulated seeds. Five combinations of Lavatera biomass characterized by different pre-sowing seed exposure times to laser light (1–30 min) were investigated. The results showed that the exposure time of, respectively, 10, 15 and 30 min had the most pronounced effect on the increase of biomass yield for two-year old shoots and the heating values for one-, two- and three-year old shoots biomass in relation to the control. Over the three experimental years, significant differences in the H, N, fixed carbon and ash content between the combinations of shoots were found. For the tested biomass after the exposition to laser light as well as for older plants, the ignition and burnout temperatures were shifted towards higher values. Stimulation with laser light affected the maximum mass loss rate as well as corresponding temperature for the investigated shoots. The two-year old combinations were characterized by better combustion index in comparison to one- and three-year old ones. As mentioned above, laser light stimulation of Lavatera seeds can contribute to the heating value and biomass yield increase and, as a result, to a more effective fossil fuel replacement.

The inessential heavy metal/loids cadmium (Cd) and arsenic (As), which often co-occur in polluted paddy soils, are toxic to rice. Silicon (Si) treatment is known to reduce Cd and As toxicity in rice plants. To better understand the shared mechanisms by which Si alleviates Cd and As stress, rice seedlings were hydroponically exposed to Cd or As, then treated with Si. The addition of Si significantly ameliorated the inhibitory effects of Cd and As on rice seedling growth. Si supplementation decreased Cd and As translocation from roots to shoots, and significantly reduced Cd- and As-induced reactive oxygen species generation in rice seedlings. Transcriptomics analyses were conducted to elucidate molecular mechanisms underlying the Si-mediated response to Cd or As stress in rice. The expression patterns of the differentially expressed genes in Cd- or As-stressed rice roots with and without Si application were compared. The transcriptomes of the Cd- and As-stressed rice roots were similarly and profoundly reshaped by Si application, suggesting that Si may play a fundamental, active role in plant defense against heavy metal/loid stresses by modulating whole genome expression. We also identified two novel genes, Os01g0524500 and Os06g0514800, encoding a myeloblastosis (MYB) transcription factor and a thionin, respectively, which may be candidate targets for Si to alleviate Cd and As stress in rice, as well as for the generation of Cd- and/or As-resistant plants. This study provides valuable resources for further clarification of the shared molecular mechanisms underlying the Si-mediated alleviation of Cd and As toxicity in rice.

Cytochrome P450 monooxygenases (CYP450s) play crucial roles in the regulation of plant growth and response to abiotic stress. However, their functions in woody trees are still largely unknown. Previously, we reported that expression of the rice cytochrome P450 monooxygenase gene OsCYP714D1 increased gibberellic acid (GA) accumulation and shoot growth in transgenic poplar. In this work, we demonstrate that expression of OsCYP714D1 improved the salt tolerance of transgenic poplar plants. Compared to wild type, plant height and K+ content were significantly higher, whereas plant growth inhibition and Na+ content were significantly lower, in transgenic plants grown under high salt stress condition. Transcriptomic analyses revealed that OsCYP714D1 expression up-regulated the expressions of GA biosynthesis, signaling and stress responsive genes in transgenic plants under both normal and high salt stress conditions. Further gene ontology (GO) analyses indicated that genes involved in plant hormone and ion metabolic activities were significantly enriched in transgenic plants. Our findings imply that OsCYP714D1 participated in the regulation of both shoot growth and salt resistance through regulating gibberellin and ion homeostasis in transgenic poplar, and it can be used as a candidate gene for the engineering of new tree varieties with improved biomass production and salt stress resistance.

Concomitant rooting and photosynthetic responses of crop plants to water availability and plant growth regulators lack clarity. Three pot-grown sesame genotypes were subjected to three irrigation regimes, ranging from control to severe moisture stress, and two levels of salicylic acid (SA) (0 and 0.6 mM) to address this lacuna of data. Drought led to decreases in gas exchange, water relation, and rooting attributes, and shoot dry mass of the three genotypes in different extents, but it resulted in increases in substomatal CO2 concentration, proline concentration, and root/shoot dry mass. Cumulative root length, root length density, specific root length, and root surface tended to increase in genotype Yekta upon experiencing stress, in contrast to more or less decreasing tendencies in rooting characters of genotypes Shiraz and Naz-Takshakhe. Such genotype-specificity led to the reversal of correlations between gas exchange attributes and rooting characteristics under drought conditions. External SA led to enhancements in gas exchange, water relation, and rooting attributes, and dry mass; the degree of the enhancements tended to be greater in the stress-stricken plants. These findings indicate that genotype Yekta benefits from rooting characteristics with drought tolerance significance and SA is effective in enhancing photosynthetic, physiological and rooting attributes, drought tolerance, and growth of sesame under drought circumstances.

Arbuscular mycorrhizal fungi (AMF) allow plants to make better use of water and minerals. This alliance concerns the majority of crops and might greatly limit their dependence on fertilizers. In this work, AMF contribution and moderate fertilization were assessed for their impact on root colonization, growth, yield, number of fruits and soluble dry matter of tomato (Solanum lycopersicum L. var. Fahla F1) in a Mediterranean agroecosystem (El-Tarf, Algeria). The soil had a low available phosphorus content and a low mycorrhizal potential. Tomato seedlings were uninoculated (M−) or inoculated (M+) with a commercial AMF inoculum. Three NPK (10.42.10) fertilizer rates corresponding to 0, 2000 and 4000 mg plant−1 were applied. Mycorrhizal inoculation significantly increased root colonization levels (+48%), height (+8.78%), shoot dry biomass (+21.5%), root dry biomass (+34.45%), total yield (+8.07%) and number of fruits (+19.05%). NPK decreased root colonization levels; however, it enhanced significantly tomato growth with the highest shoot dry biomass obtained with 2000 mg plant -1. Total yield and number of fruits increased with increasing NPK rate; the highest yield occurred with 4000 mg plant−1. Soluble dry matter was not affected by AMF or NPK. Tomato inoculation combined to a reduced fertilization can provide appreciable gains in terms of growth and yield in a low P soil with a low mycorrhizal potential, which enhances agricultural sustainability due to a decreased impact of fertilizers.

Seed germination is the beginning of a new lifecycle, and involves many complex physiological and biochemical reactions including seed reserve mobilization in the endosperm and nutrient transport and reuse in the embryo. Although glutelin is a dominant storage protein in rice, its contribution to seed germination and its regulatory mechanisms are mostly unknown. Gibberellin (GA) and brassinosteroid (BR), two major growth-promoting phytohormones, also play positive roles in controlling seed germination. However, how GA and BR interact and coordinate seed germination and facilitate glutelin mobilization remains unclear. In the present study, biochemical and physiological analyses of seed germination indicated that both GA and BR promote seed germination and post-germination growth. Exogenous application of GA restored germination defects caused by BR deficiency or insensitivity. Proteomic and qRT-PCR results showed that the expression of several glutelin proteins and their encoding genes was induced by BR and GA in the embryo. Expression assays suggested that the increased accumulation of glutelin protein in the embryo was due to the accelerated degradation of glutelin by a cysteine proteinase (REP-1) in the endosperm. The breakdown of glutelin in the endosperm showed a strict positive correspondence with the length of the shoot. The GluA2 mutation led to reduced degradation rate of glutelin and defects in seed germination, and the promotion effect of GA on seed germination was weakened in the glua2 mutant. In vitro culture assay of rice embryos showed that glutelin mobilization functioned downstream of the GA and BR pathways to promote shoot elongation. These findings suggest a mechanism that mediates crosstalk between BR and GA in co-regulating rice seed germination and embryo growth.

The sulfhydryl bioregulator thiourea (TU) is effective in ameliorating the negative impact of different abiotic stresses in plants. To explore the significant performance of TU (5 mM TU, as foliar spray) in conferring mild (25% depletion of water from field capacity, FC), moderate (50% depletion from FC) and severe (75% depletion from FC) drought stress (applied at 25 days after sowing), physiological and biochemical responses of two chickpea (Cicer arietinum L.) cultivars (cv. BARI Chola-7 and BARI Chola-9) were investigated in the current study. Shoot fresh weight, dry weight, chlorophyll content and leaf relative water content reduced noticeably in mild, moderate and severe drought stresses over control. A sharp increase of H2O2 accumulation, thiobarbituric acid reactive substances and proline content were noticed at any level of drought stress which further declined in TU-treated drought-stressed plants. Thiourea-foliar application also increased ascorbate and glutathione contents and upregulated antioxidant enzyme activities, compared to drought-stressed plants alone. Thiourea-induced increased glyoxalase I and glyoxalase II activities are the indications of upregulated methylglyoxal detoxification system. Enhancement of antioxidant defense and glyoxalase system, osmoregulation and protection of photosynthetic pigments by TU improved growth, imparted oxidative stress tolerance, ameliorated ROS toxicity and improved physiology of chickpea plants under drought stress.

Nowadays, among several abiotic stresses, salt, especially NaCl and UV-B are of major concern. They lead to deleterious effects on plant growth and ultimately affect crop productivity. The present study was planned to find out some ameliorative solution against these stresses. Here, the modulatory action of two oxylipins, namely, methyl jasmonate (MeJA) and 12-Oxo-phytodienoic acid (OPDA) on growth, photosynthetic performance, nitrate/ammonia assimilating enzymes, and nutritive values of Luffa Mill. seedlings grown under NaCl (20 and 40 mM) and/or enhanced UV-B stresses (ambient: 8.2 kJ m−2 d−1 + additional: 2.2 kJ m−2 s−1) were analyzed. Both the stresses when given alone, negatively affected the fresh mass, root/shoot ratio, leaf area, photosynthetic pigments content, photosynthetic oxygen yield and, chlorophyll a fluorescence kinetic parameter. This decline was further aggravated upon combined exposure to the stressors. However, supplementation of MeJA/OPDA effectively counteracted the negative impact on important growth-regulating processes. The activities of nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), and glutamate synthase (GOGAT) enzymes, as well as the contents of inorganic nitrogen, protein, and carbohydrate, were increased with the supplementation of MeJA/OPDA. The increase in the Na+ and Cl‾ contents due to NaCl or/and UV-B was depreciated by MeJA or OPDA. Ameliorating behaviour of MeJA or OPDA is correlated with improved photosynthetic activity and nitrogen metabolism. These findings, point out that supplementation of MeJA/OPDA, particularly OPDA more favourably regulated the growth-promoting activities, which can be linked with the mitigation of NaCl and UV-B stress.

Barnyardgrass (Echinochloa spp.) is the most common noxious weed in rice paddies as it inhibits rice growth and reduces grain yield. To date, little information is available on above- and belowground-growth changes in rice due to neighboring barnyardgrass. This study aimed to investigate the changes in root traits and shoot growth of rice when it is grown with different kinds of barnyardgrass. Japonica rice plants (var. Nanjing 9108) were co-cultured with two varieties of Echinochloa crusgalli (L.) Beauv. (EP, var. mitis (pursh) Petern; EH, var. zelayensis (H.B.K.) Hitchc), and E. colonum (L.) Link (EL) in the field in 2017 and 2018. Four treatments included control (i.e., weed free rice plants) and co-cultures with each of three barnyardgrasses (EP, EH, and EL). The results revealed that EP, EH, and EL treatments significantly reduced rice grain yields by 30.6%–36.2%, 42.5%–46.5%, and 10.6%–14.3%, respectively. Shoot growth including shoot dry weight, leaf photosynthetic rate, zeatin (Z) and zeatin riboside (ZR) in grains, and activities of key enzymes involved in sucrose-to-starch conversion in grains and root traits, such as length density, root dry weight, total absorbing surface area, active absorption surface area, oxidation activity, and Z + ZR contents in roots were dramatically reduced during post-heading stages of rice when grown with the three kinds of barnyardgrass. Moreover, above-mentioned rice shoot growth indices were strongly and positively correlated with root traits. These results suggested the decrease in rice shoot growth and root traits during post-heading stages contributes to the reduction in the rice yield when it grows with barnyardgrass neighbors.

SENSITIVE TO PROTON RHIZOTOXICITY 1 (STOP1) is a master transcription factor (TF) that regulates genes encoding proteins critical for cellular pH homeostasis. STOP1 also causes pleiotropic effects in both roots and shoots associated with various stress tolerances. STOP1-regulated genes in roots synergistically confer tolerance to coexisting stress factors in acid soil, and root-architecture remodeling for superior phosphorus acquisition. Additionally, STOP1 confers salt tolerance to roots under low-potassium conditions. By contrast, STOP1 antagonistically functions in shoots to promote hypoxia tolerance but to suppress drought tolerance. In this review, we discuss how these synergetic- and antagonistic-pleiotropic effects indicate that STOP1 is a central hub of stress regulation and that the harmonization of STOP1-regulated traits is essential for plant adaptation to various environments.

Tissue loss of plants caused by herbivores is very common in nature. As the storage and first photosynthetic organ, the loss of cotyledon severely impacts dicot seedling establishment and the subsequent growth. However, it is still not clear how plants adjust their metabolic strategy in response to cotyledon loss. In this study, we employed ICP-OES, GC and LC-MS to examine the effects of cotyledon removal (RC1: remove one cotyledon, RC2: remove two cotyledon) on mineral element distribution and metabolite changes in a traditional Chinese herbal plant, Astragalus membranaceus. The results showed that cotyledon removal had a greater effect on shoot than root growth. Specifically, RC2 revealed a more serious impact on shoot growth than RC1. Microelement Mn and Na in shoot increased more in RC2 than RC1. Macroelement K and microelement B in root increased in RC2. The metabolite results in shoot showed that sugars related to galactose metabolism reduced while amino acids significantly increased in RC2. In root, sugars related to fructose and mannose metabolism decreased in both RC1 and RC2 while most flavonoids increased in RC2. It can be concluded that cotyledon removal triggered different metabolic strategies in both root and shoot. In shoot, more Mn was absorbed to improve the lowered photosynthetic efficiency. Meanwhile, increased Na may have promoted carbohydrate consumption and amino acid synthesis, thereby maintaining shoot growth. In root, K and B participation in cell division and expansion increased, as well as the delivery and metabolism of carbohydrates, to maintain root system growth.

Karrikinolide (KAR1), identified in biochars, has gained research attention because of its significant role in seed germination, seedling development, root development, and abiotic stresses. However, KAR1 regulation of salt stress in wheat is elusive. This study investigated the physiological mechanism involved in KAR1 alleviation of salt stress in wheat. The results showed KAR1 boosted seed germination percentage under salinity stress via stimulating the relative expression of genes regulating gibberellins biosynthesis and decreasing the expression levels of abscisic acid biosynthesis and signaling genes. As seen in seed germination, exogenous supplementation of KAR1 dramatically mitigated the salt stress also in wheat seedling, resulting in increased root and shoot growth as measured in biomass as compared to salt stress alone. Salt stress significantly induced the endogenous hydrogen peroxide and malondialdehyde levels, whereas KAR1 strictly counterbalanced them. Under salt stress, KAR1 supplementation showed significant induction in reduced glutathione (GSH) and reduction in oxidized glutathione (GSSG) content, which improved GSH/GSSG ratio in wheat seedlings. Exogenous supplementation of KAR1 significantly promoted the activities of enzymatic antioxidants in wheat seedlings exposed to salt stress. KAR1 induced the relative expression of genes regulating the biosynthesis of antioxidants in wheat seedlings under salinity. Moreover, KAR1 induced the expression level of K+/Na+ homeostasis genes, reduced Na+ concentration, and induced K+ concentration in wheat seedling under salt stress. The results suggest that KAR1 supplementation maintained the redox and K+/Na+ homeostasis in wheat seedling under salinity, which might be a crucial part of physiological mechanisms in KAR1 induced tolerance to salt stress. In conclusion, we exposed the protective role of KAR1 against salt stress in wheat.

As one of the main vegetable crops cultivated in the world, the tomato has advantages of high yield and economic benefits, and plays an important role in promoting farmers' income and social and economic growth. However, lateral branches during the growth process of tomato consume considerable nutrients and reduce the yield of tomato. Phytohormones such as strigolactone and auxin can inhibit the formation of lateral branches. However, the mechanism of their interaction is not particularly clear. To better understand the effects of exogenous strigolactone and auxin on tomato, proteome analyses of tomato shoots treated with exogenous GR24 and indole acetic acid were performed using an integrated approach involving tandem mass tag (TMT) labeling and liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). We identified 6685 proteins, of which 5822 contained quantitative information. Many differentially expressed proteins (DEPs) were found in different comparisons, including 415, 148, and 130 DEPs in GR24 vs mock, IAA vs mock, and GR24 + IAA vs mock comparisons, respectively. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that ‘photosynthesis - antenna proteins’ were significantly enriched in three treatments. Our data can help reveal the interaction between strigolactone and auxin in tomato seedlings.

Alfalfa (Medicago sativa L.) has the advantages of high yield and nutritional value as a perennial forage. However, one of the drawbacks of alfalfa is its susceptibility to drought conditions, which is a global problem in agriculture. The purpose of this study was to reveal the effects of exogenous PopW, a harpin protein from Ralstonia solanacearum, treatment on growth parameters, physiological and biochemical mechanism of alfalfa under drought-stress conditions. Growth parameters, relative water content, free proline, leaf area, total chlorophyll, antioxidative enzymes, endogenous hormones including ABA, CTK, GA, JA, SA and IAA were determined in response to exogenous PopW treatment under drought stress in alfalfa cultivar (Victoria). Moreover, relative gene expressions of drought-related and leaf senescence genes were determined. Under drought stress, alfalfa plants had lower shoot dry weight, shoot length, relative water content, leaf area, and total chlorophyll content, compared to control (non-stressed). However, Exogenous PopW treatment significantly increased growth values, relative water content, free proline, leaf area, total chlorophyll content, catalase, glutathione reductase and superoxide dismutase under drought conditions, compared to control and drought stress alone. Moreover, exogenous PopW treatment significantly increased ABA, GA, JA, SA, IAA contents, up-regulated auxin- and drought-responsive genes, down-regulated leaf senescence genes. Exogenous PopW treatment enhanced drought stress tolerance of alfalfa due to changes of endogenous hormone contents and expression levels of drought stress and leaf senescence genes. The results of the study show that PopW treatment could be used to increase the forage yield of alfalfa on areas having drought problem.

Cadmium (Cd) is a heavy metal which causes environmental pollution and affects physiological and morphological characters of plants. Sodium nitroprusside is generally used as Nitric Oxide (NO) donor in plants. A glasshouse pot experiment was carried out to investigate the effect of exogenous NO on physiological, biochemical and enzyme activity of savory plants under Cd stress. Experimental factors included soil contamination with cadmium chloride (0 control, 75, 100 and 150 µM) and NO foliar application in four concentrations (0 control, 50, 100 and 200 µM). The results showed that Cd stress decreased growth parameters including plant height, number of leaves and lateral branch, 25.97%, 19.18% and 22.39%, respectively. In contrast, proline accumulation, membrane cell leakage, carbohydrates and antioxidant enzymes activity were increased. While NO application improved savory plant growth under Cd stress. NO application improved growth of plants under all Cd concentration for example under highest Cd concentration (150 μM) foliar application of 200 μM NO, proline, chlorophyll (a , b and carotenoid), carbohydrates and peroxidase activity were 116.48%, 56.25%, 38.38%, 48%, 140% and 85.78% compared to relative control increased, respectively. Also, NO application (200 µM) reduced the Cd accumulation in the shoot and roots of plants.

High levels of dissolved SO4 in drinking water can adversely affect livestock performance. Some plant species may help to remove SO4 and cleanse drinking water, especially S-hyperaccumulators. However, little is known about the capacity of S-hyperaccumulators to grow in rangeland wetland environments. Here we measured plant properties, S concentration, and S mass of nine plant species. Plants were grown in a wetland environment on an artificial floating island (AFI) in a mesocosm supplied with high SO4 water (2 430−4 730 parts per million [PPM]) from a rangeland reservoir. Water properties were measured throughout the experiment. We also used our data and data from the literature to parameterize simulations and estimate the number of plants (per L) needed to reduce the SO4 concentration from 2 000 PPM to a recommended limit of 1 000 PPM. The average sulfur concentration of the nine species was 3.8 times greater than the average of 39 species from the literature. Among the nine species, Brassica napus L., B. napus var. pabularia (DC.) Rchb., and Brassica septiceps (L. H. Bailey) L. H. Bailey tended to have the greatest shoot S concentrations. The total S mass per plant was 5 times greater for B. septiceps (44 mg × plant−1) than B. juncea (L.) Czern. We found no other appreciable differences in total S mass among species. The simulations suggest that ≥ 1.9 plants × L−1 of B. septiceps or ≥ 0.6 plants × L−1 of B. oleracea L. would be needed to reduce the water's SO4 concentration from 2 000 PPM to the recommended limit. Given the small amount of S removed (per plant) relative to the vast amount of dissolved SO4 possible in rangeland water sources, planted AFIs are not likely to be a practical tool for reducing SO4 in livestock drinking water. Conversely, water treatment systems may be justified in some cases.

Bulbophyllum odoratissimum (Sm.) Lindl. ex Wall. is widely used as traditional medicine for the treatment of tuberculosis, chronic inflammation and is listed as an endangered orchid due to over-exploitation and habitat destruction. The present study was carried out to establish a genetically stable in vitro regeneration protocol for mass multiplication using nodal segments and to determine phytochemical constituents, the antioxidant capacity of different parts (leaf, pseudobulb and root) of mother plants and acclimatized in vitro raised plants of B. odoratissimum. The synergistic effect of BA (4.0 mgl−1) and IBA (0.5 mgl−1) was found to be optimum for producing maximum shoot proliferation. IBA was found to be more effective for root proliferation than IAA, NAA and an average (3.08 roots/shoot) was obtained in 0.5 mgl−1 IBA. The well rooted plantlets were successfully acclimatized (more than 90% survival rate) in greenhouse, exhibiting normal development. The ISSR banding profiles confirmed high degree of genetic homogeneity among the clones. Extraction of all plant material from both mother plant and in vitro raised plant possess relevant TPC, TFC, radical scavenging activity (DPPH and ABTS) as well as total reducing power ability. HPLC chromatogram exhibited that phytochemical compounds detected in regenerated plants were similar to those present in mother plant and there was no remarkable difference. High regeneration frequency along with its genetic stability and secondary metabolite production validate the efficiency of this micropropagation protocol of B. odoratissimum for species recovery program as well as a potential source of commercial application.

Vitis vinifera 87-1 plants infected by grapevine fleck virus (GFkV) and grapevine rupestris stem pitting-associated virus (GRSPaV) were used as the plant materials for virus elimination treatment. This study evaluated the effects of ribavirin at different concentrations (15 and 25 µg mL−1; R15 and R25, respectively), thermotherapy (37°C; T), and the combination of ribavirin and thermotherapy (R15+T and R25+T) on eliminating viruses from grapevine plants in vitro. Both R15 and R25 had phytotoxic effects and weakened plant growth. Thermotherapy positively affected the growth of grapevine plants. Plant height was significantly greater in T, R15+T, and R25+T than in CK, R15 and R25. The proportion of dead plants after T, R15+T, and R25+T was 51.4, 11.4, and 8.6%, respectively. The survival rates of regenerated plants after all treatments were >68.0%. Ribavirin concentration and treatment time were related to the regeneration of shoot tips and elimination efficiencies of the two viruses. The survival rates of plants after R15+T for 30, 40, and 50 days were 97.3, 90.7, and 74.4%, respectively. The elimination rates of GRSPaV from plants in the three time quantum were 55.6, 84.6, and 93.8%, respectively. The elimination rate of GFkV was 23.9% higher in R25 (35/44) than in R15 (25/45), and that of GRSPaV was 7.0% higher in R25 than in R15. The combination of thermotherapy and chemotherapy was found to have a positive effect on the eradication of GFkV and GRSPaV, and R25+T for 50 days was able to completely eliminate the two viruses from in vitro grapevines.

Salinity is a crucial limiting factor behind crop production in the world. Understanding the mechanisms of salinity-stress response could contribute to the improvement of salt tolerance in plants. We assessed the effect of salinity treatment (0, 100 and 200 mM), 24 h, 3 days, and 3 weeks after salt exposure on morphological characters and gene expression pattern of two barley cultivars; Sahara and Clipper and a new Advanced line. The expression pattern of 8 salt-inducible genes namely βFRUCT3, L1s1, HSP17.8, AOS, SBP, PEAMT, Na+-transporter, and ATLS1) was investigated in barley shoots using the real-time RT-PCR. Plant height, number of leaf/plant, number of tiller/plant, shoot fresh and dry weight and shoot water content were measured. The NaCl treatment significantly affects shoot fresh and dry weight as well as shoot water content and significant differences were observed among genotypes for all the studied traits except shoot dry weight and number of leaf/plant. The expression of the studied genes except ATLS1 was significantly affected by salt treatment, genotype and timepoint exposure to salinity. The mRNA level of βFRUCT3, L1s1, PEAMT and Na+-transporter genes was up-regulated in the salt-tolerant cultivar Sahara and down-regulated in the salt-sensitive cultivar Clipper after 3 weeks exposure to salt treatment.

In plants, the shoot apical meristem (SAM) is essential for the growth of aboveground organs. However, little is known about its molecular responses to abiotic stresses. Here, we show that the SAM of Arabidopsis thaliana displays an autonomous heat-stress (HS) memory of a previous non-lethal HS, allowing the SAM to regain growth after exposure to an otherwise lethal HS several days later. Using RNA sequencing, we identified genes participating in establishing the SAM's HS transcriptional memory, including the stem cell (SC) regulators CLAVATA1 (CLV1) and CLV3, HEAT SHOCK PROTEIN 17.6A (HSP17.6A), and the primary carbohydrate metabolism gene FRUCTOSE-BISPHOSPHATE ALDOLASE 6 (FBA6). We demonstrate that sugar availability is essential for survival of plants at high temperature. HEAT SHOCK TRANSCRIPTION FACTOR A2 (HSFA2A) directly regulates the expression of HSP17.6A and FBA6 by binding to the heat-shock elements in their promoters, indicating that HSFA2 is required for transcriptional activation of SAM memory genes. Collectively, these findings indicate that plants have evolved a sophisticated protection mechanism to maintain SCs and, hence, their capacity to re-initiate shoot growth after stress release.

Among the Orchidaceae is found the Cattleya, an important genus for commercial hybrid production. However, many Cattleya species are facing extinction due to over-collection and habitat loss. Cattleya elongata is a species endemic to Bahia; these plants have attractive brownish-purple tepals and an attractive purple labellum. This species has been submitted to collections; however, it is not easy to grow in vitro, and as such, it is rarely cultured. This work aimed to determine the best conditions for plant production and acclimatization to allow either commercialization or reintroduction. Germinated seeds were sown in three different culture media, Knudson C (Kc), Murashige and Skooge (½-concentration MS) and Vacin and Went (VW) media, and grown for 270 days. The length of the roots and shoots and their fresh matter were determined, and survival in culture media and acclimatization were also scored. The in vitro development of C. elongata was best in the ½-concentration MS and VW media. The best choice for C. elongata propagation was the ½-concentration MS, as they were superior either for in vitro development or for acclimatization.