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This study investigated the mitigating effects of spermidine (Spd) application on salinity-induced ion inbalance, physiological properties, and the expression of some genes in foxtail millet (Setaria italica L.). We observed 30-d-old seedlings maintained at a half-strength Hoagland solution (control), 1.0 % NaCl, 10, 20, and 40 μM Spd, and 10, 20, and 40 μM Spd + 1.0 % (m/v) NaCl for 14 d. The results show that salt stress significantly inhibited plant growth, and this was significantly ameliorated by Spd. The mass of the shoots and roots, content of chlorophyll a and chlorophyll b, root activity, and K+ content were higher whereas Na+ content, Na+/K+ ratio, relative electrolyte leakage, glutathione content, H2O2 content, activity of glutathione reductase (GR), and catalase (CAT) were lower after application of Spd in comparison with NaCl alone. The expression of GR, ascorbate peroxidase, CAT, and superoxide dismutase genes also significantly decreased in salt stressed plants with Spd. This study has proved the role of Spd in alleviating salt stress in foxtail millet and identified that 20 μM Spd was most effective.

Bread wheat spring cultivar Saratovskaya 29 (S29) is a highly drought tolerant. S29, five single chromosome substitution and two introgression lines of this cultivar for chromosomes of second homoeological group were grown in a climatic chamber under optimal and water deficit conditions of water supply. The donor of the three homologous chromosomes 2A, 2B and 2D was the German spring cultivar Yanetskis Probat; the donors of chromosome 2D were the old spring varieties of Western Siberia, Caesium 111 and Sibirka 1818. The donors of 2A chromosome were the species Triticum timopheevii and Aegilops markgrafii. Eleven physiological indexes including water use efficiency, the chlorophyll a, chlorophyll b and carotenoids contents, osmotic substances contents, antioxidant enzymes activities and lipoxygenase activity were measured in leaves of wheat at the stage of beginning of earing. To assess genotypes, we established a comprehensive evaluation value (D) based on various measured physiological parameters and shoot biomass. The D positively correlated with the tolerance of shoot biomass (r = 0.955, P

Light-emitting diodes (LEDs) have recently been widely used as light sources for the cultivation of plants in controlled environments. However, before LEDs can be used as the sole light source, it is imperative that soybean (Glycine max) response to light quality be well characterized. The objective of the present work was to investigate how soybean seedlings respond to different blue (B) and red (R) photon flux ratios (PFR) using LEDs. Light treatments were comprised of 170 ± 5 μmol m−2 s−1 photosynthetic photon flux density with B:R ratios of 0B:100R%, 10B:90R%, 25B:75R%, 50B:50R%, 80B:20R%, 90B:10R%, and 100B:0R%. Our results suggest that with the increase in B PFR from 0 to 90%, both plant height and specific leaf area inclined to decline while stem diameter gradually increased. The plants exposed to 80B:20R% showed unexpectedly greater total root length, root surface area, root volume, number of root tip, plant dry mass, leaf dry mass, root dry mass, leaf mass fraction and root mass fraction than plants exposed to all other treatments. Plants grown with 0B:100R% had the highest content of chlorophyll b (Chl b) and content of total chlorophyll [Chl (a + b)] but possessed the lowest ratio of the content of chlorophyll a to the content of chlorophyll b (Chl a/b). Plants grown with R alone also showed the lowest chlorophyll fluorescent parameters. The light-saturated CO2 assimilation rate (Asat) and the light-saturated stomatal conductance (gssat) for 0B:100R% were, respectively, 64.85% and 203.23% lower than those for 80B:20R%. However, plants grown with sole R accumulated higher soluble sugar and starch content during the daytime. Collectively, our results suggest that compared to R- or B-LED alone, an appropriate combination of R and B promotes plant growth and photosynthetic performance for soybean.

A field experiment was conducted during Kharif 2018 at Zonal Agricultural and Horticultural Research Station, Hiriyur, University of Agricultural and Horticultural Sciences, Shivamogga to study the effect of different levels of hydrogel, farm yard manure (FYM) and mulching on chlorophyll a, chlorophyll b, total chlorophyll content and chlorophyll stability index of groundnut under rainfed condition. The experiment was laid out in a Randomized Complete Block Design (RCBD) with ten treatments replicated thrice. The results revealed that, treatment with application of recommended dose of fertilizers (RDF) along with hydrogel @ 4 kg ha-1 and FYM @ 10 t ha-1 recorded significantly higher Chlorophyll ‘a’, Chlorophyll ‘b’, total chlorophyll content (before and after boiling) and higher chlorophyll stability index at different growth stages. However, significantly lower CSI was noticed in the treatment with application of RDF alone.

Los hidrocarburos aromáticos tienen un alto potencial toxicológico, por lo que su evaluación en organismos acuáticos es de gran importancia. La microalga Chlorella vulgaris fue seleccionada, por ser una de las especies de algas más dominantes en el agua y por su potencial para degradar o absorber diferentes xenobióticos. El objetivo fue evaluar la toxicidad en C. vulgaris expuesta a fenantreno (PHE), evaluando parámetros fisiológicos como la densidad celular, contenido de clorofila a y clorofila b y actividad enzimática de superóxido dismutasa (SOD) y catalasa (CAT) que definan respuestas tóxicas a corto plazo. Se evaluaron cinco diferentes concentraciones (0,1; 1,0; 10; 100 y 1000 µg PHE. L-1), un tratamiento control solvente (acetona) y control (sin aditamentos) durante siete días. En todas las respuestas fisiológicas se observó un comportamiento dosis dependiente, disminuyendo progresivamente con el incremento de las concentraciones de PHE. La densidad celular, tasa de crecimiento, diámetro celular y clorofila pueden ser considerados biomarcadores de toxicidad. La actividad de CAT y SOD en C. vulgaris disminuyó considerablemente durante todo el periodo de estudio, posiblemente a causa de una excesiva producción de especies reactivas de oxígeno generadas por la exposición a fenantreno provocando la inhibición de estas enzimas antioxidantes. A pesar de la toxicidad de este hidrocarburo evidentemente observada en este estudio, C. vulgaris presenta una alta resistencia y adaptación a este contaminante, por lo que se puede decir que este microorganismo tiene la capacidad de evidenciar efectos toxicológicos en un entorno con este contaminante en un corto periodo de tiempo.

Background Salinity has a negative effect on the productivity of many crops. Therefore, the present study was conducted to investigate the effect of pre-soaking in different concentrations of tryptophan (0.0, 2.5, and 5.0 mM) on growth, yield and root quality of two sugar beet cultivars (DS-9004 and LP-15) under different salinity levels (320, 2000, 4000, 6000, and 8000 ppm) in an effort to reduce salinity damage on sugar beet. The data were collected at 2 stages of growth (75 and 180 days after sowing). Results The results revealed that the pre-soaking in tryptophan treatments (2.5 mM) were the most effective treatments under different salinity levels and caused significant increases in all tested parameters of this study. Moreover, increasing salinity levels decreased significantly the root purity parameters and increased impurity parameters of sugar beet. The DS-9004 cultivar gave the highest values of all studied parameters compared with the LP-15 cultivar under different salinity levels with tryptophan (2.5 mM). Chlorophyll a content and chlorophyll a/b ratio, as well as carotenoids content, were highest in DS-9004 cultivar, while chlorophyll b content was highest in LP-15 cultivar at 75 days. Conclusions Salinity level up to 320 ppm positively affected the growth yield of sugar beet while the highest significant reduction was associated with increasing salinity up to 8000 ppm. Thus, pre-soaking in tryptophan (2.5 mM) has a promotive effect on increasing sugar beet yield under water salinity conditions.

Drought is a serious global problem of agriculture. For this, an investigation was carried out with 25 wheat genotypes composed of cultivars and advanced lines to screen drought-tolerant bread wheat genotypes using multivariate analysis. The experiment was conducted in a split plot design with three replications and two treatments control and drought. The analysis of variance revealed significant differences among the genotypes and treatments for all the characters studied, viz. plant height, flag leaf collar height, flag leaf length, flag leaf breadth, chlorophyll a, chlorophyll b, proline content, number of tillers per plant, root fresh weight, shoot fresh weight and root–shoot ratio. High heritability was observed for all the traits except flag leaf length, flag leaf breadth and number of tillers per plant. Based on the genetic distances, all the 25 genotypes were grouped into three different clusters. In control conditions, cluster number I contained most tolerant genotypes and under drought conditions, cluster number III contained most drought-tolerant genotypes. In biplot, the genotypes SATYN-24, BARI Gom-24 and SATYN-2 contributed positively and correlated with number of tillers per plant, shoot fresh weight, flag leaf breadth, proline content and plant height under drought conditions. The drought susceptibility index (DSI) indicated that the genotypes BARI Gom-24 and SATYN-9 exhibited a highly drought-tolerant genotype in the present investigation. These genotypes might carry genes for drought tolerance and may be useful for further drought tolerance breeding.

Pots experiment was designed in two summer successive seasons of 2017 and 2018 at the wire house of the Agric. Bot. Dept., Fac. Agric. Zagazig Univ., Sharkia Governorate, Egypt. Common bean plants cv. Giza 3 were foliar sprayed with different concentrations of humic acid, proline, naphthalene acetic acid and distilled water (as a control) under sea water salinity levels, i.e. 1000, 2000 and 3000 ppm and tap water (500 ppm) as a control, to examine its effects on growth, photosynthetic pigments, proline content, yield and leaf anatomy of common bean plants. Results revealed that most studied traits, i.e., plant height, number of leaves/plant, leaf area, fresh weight of roots, stems and leaves, photosynthetic pigments (chlorophyll a, chlorophyll b, chlorophyll a+b and carotenoids) and yield expressed as number of pods/plant, number of seeds/pod, number of seeds/ plant, 100-seed weight and length of pod as well as leaf anatomical parameters. Most aforementioned features were significantly decreased with increasing sea water levels up to the highest level (3000 ppm) comparison with control (tap water). On the contrary, proline content in leaves was increased with increasing salinity levels up to 3000 ppm. On the other hand, spraying common bean plants with humic acid at 2 and 4g/L, proline at 50 and 100 ppm and naphthalene acetic acid at 25 and 50 ppm had a positive significant effect in most studied traits compared to control (distilled water). In general, the most favorable treatments were foliar spray common bean plants with humic acid at 2g/L followed by proline at 100 ppm then naphthalene acetic acid at 25 ppm, respectively compared to control (distilled water). It could be concluded that spraying of humic acid, proline and naphthalene acetic acid mitigate the harmful effect of sea water salinity on common bean plants and the best treatment was interaction between irrigation with tap water or sea water at 1000 ppm and spraying by humic acid at 2 g/L.

Air quality is getting poor day by day due to air pollution. Automobile exhaust pipe emission has been a major contributor to the problem of air pollution in the present scenario. This study was aimed for observing the effects of exhaust pipe emissions on chlorophyll, which is the most important plant pigment. Lemon plants were given exposure to exhaust emissions from vehicles using fuel types in open top chambers for the set duration of time. Determination of total chlorophyll, chlorophyll a and chlorophyll b and leaf biomass of all exposed population of lemon was done. Decrease in chlorophyll content was observed in all exposed plants with maximum reduction noticed in those exposed to exhaust from diesel using vehicle. Leaf biomass was also reduced in exposed population. Exposure to harmful exhaust emissions causes changes in normal physiology of plant and alters its responses. Keywords : Air pollution, automobile exhaust, chlorophyll content, lemon Cite this Article S Kaur. Studies on the impact of automobile exhaust emissions (from vehicles using diesel and petrol) on chlorophyll content and leaf biomass of lemon. Research & Reviews: A Journal of Life Sciences . 2020; 10(1): 1–4.

The artificial light source is one of the most important factors in a controlled environment for vegetable production. It could provide new opportunities to improve growth and increase phytochemicals content in vegetables. Therefore, this study focused on the effects of artificial light sources on growth and phytochemicals in green oak lettuce (Lactuca sativa). The plants were grown under growth chamber with three artificial light sources, namely bar-LED (the 1:1:1 ratio of blue 460 nm : red 630 nm : red 660 nm), bulb-LED (the 2:1:1 ratio of blue 460 nm : red 630 nm : red 660 nm), and fluorescent lamp (FL) (the wavelength range 380-700 nm) for 4 weeks. The quality of bar-LED light was better than either bulb-LED or FL, when assessed by the parameters of photosynthetically active radiation (PAR), photosynthetic photon flux density (PPFD, 400-700 nm), PPFD-B (blue, 400-500 nm), PPFD-R (red, 600-700 nm), the yield photon flux density (YPFD), and the color of red. However, shoot and root (fresh and dry mass), leaf area, leaf number, and shoot/root ratio did not significantly differ between plants grown under bar-LED and bulb-LED, but they were significantly higher than plants grown under FL. Bulb-LED and bar-LED induced larger dry mass of the plants than FL. The dry mass per mole of artificial lighting was highest in plants grown under bar-LED. On the other hand, the fresh mass per mole of artificial lighting was highest in plants grown under bulb-LED. As regards power consumption, bar-LED provided the lowest consumption with 44.4% energy saving over the FL. Total phenolic content, 2,2’-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) and 2,2-diphenylpicrylhydrazyl (DPPH) activities were highest in plants grown under bar-LED. FL lighting gave the least contents of chlorophyll a and chlorophyll a + b. However, chlorophyll b and carotenoid contents did not significantly differ among the treatments. Thus, the results suggested that bar-LED has the potential to improve energy saving, and both growth and phytochemicals content of green oak lettuce grown in a controlled environment of vegetable production. RESUMO A fonte de luz artificial é um dos fatores mais importantes em um ambiente controlado para a produção de vegetais. Ela pode melhorar o crescimento e aumentar o conteúdo de fitoquímicos nos vegetais. Portanto, este estudo enfocou os efeitos de fontes de luz artificiais no crescimento e fitoquímicos em alface green oak (Lactuca sativa). As plantas foram cultivadas em câmara de crescimento com três fontes de luz artificial, a saber: bar-LED (proporção 1:1:1 de azul 460 nm: vermelho 630 nm: vermelho 660 nm), bulb-LED (proporção 2:1:1 de azul 460 nm: vermelho 630 nm: vermelho 660 nm) e lâmpada fluorescente (FL) (faixa de comprimento de onda 380-700 nm) por 4 semanas. A qualidade da luz de bar-LED foi melhor que a de bulb-LED ou FL, quando avaliada pelos parâmetros de radiação fotossinteticamente ativa (PAR), densidade de fluxo de fótons fotossintéticos (PPFD, 400-700 nm), PPFD-B (azul, 400-500 nm), PPFD-R (vermelho, 600-700 nm), densidade do fluxo de fótons (YPFD) e cor vermelha. No entanto, a parte aérea e a raiz (massa fresca e seca), a área foliar, o número de folhas e a relação parte aérea/raiz não diferiram significativamente entre as plantas cultivadas sob bar-LED e bulb-LED, mas foram significativamente maiores que as plantas cultivadas sob FL. O bulb-LED e o bar-LED induziram maior massa seca das plantas que o FL. A massa seca por mole de iluminação artificial foi maior nas plantas cultivadas sob bar-LED. Por outro lado, a massa fresca por mole de iluminação artificial foi maior nas plantas cultivadas sob bulb-LED. Em relação ao consumo de energia, o bar-LED forneceu o menor consumo, com 44,4% de economia de energia em relação ao FL. O conteúdo fenólico total, as atividades 2,2’-azino-bis (ácido 3-etilbenztiazolina-6-sulfônico) (ABTS) e 2,2-difenilpicliril-hidrazil (DPPH) foram maiores nas plantas cultivadas sob bar-LED. A iluminação FL resultou em menor conteúdo de clorofila a e clorofila a + b. No entanto, os teores de clorofila b e carotenóide não diferiram significativamente entre os tratamentos. Assim, os resultados sugeriram que o bar-LED tem potencial para maior economia de energia e o conteúdo de fitoquímicos e crescimento de alface green oak cultivada em ambiente controlado de produção vegetal.

This study examined the effect of chitosan elicitor with four different concentrations (0, 0.2, 0.4 and 0.6 g/l) on physiological and biochemical properties of stevia under four levels of salinity stress (0, 50, 100, 150 mM level of NaCl). Salt stress caused reduction of chlorophyll a (Chl a), chlorophyll b (Chl b), total chlorophyll, carotenoid and total protein content. The increment of malondialdehyde (MDA) content was not significant in all NaCl levels, while the CAT and POX activities were increased as well as stevioside and rebaudioside A under salinity stress. On one side, chitosan treatments could compensate the reduction of physiological traits such as photosynthetic pigments and protein content. On the other side, chitosan caused multiple increases in malondialdehyde content, antioxidant enzymes activity (catalase and peroxidase), steviol glycosides (stevioside and rebaudioside A) under salt stress. We report for the first time, the potential of chitosan to enhance salinity-tolerant abilities in stevia through increment of the salt-adaptive factors and to diminish harmful damages caused by NaCl stress.

This study was aimed to investigate how exogenous manganese (Mn) would limit damage in the oxygen-evolving complex (OEC) and photosynthetic apparatus of maize seedlings caused during seawater vulnerability. In this study, seawater was applied in 2-week-old maize (Zea mays L.) seedling, and the degree of damage of photosynthetic pigment pool, the OEC, and net electron transport rate were observed. Mn supplement was also added in maize seedlings to limit the damage of the OEC and photosynthetic apparatus caused during salinity. Leaf relative water content (RWC), fresh weight (FW), and photosynthetic pigment pool (chlorophyll a, chlorophyll b, and carotenoids) sharply declined after 7 days of treatment; however, Mn supplement increased these values. Chlorophyll fluorescence induction (OJIP) transients showed low Fv/Fo, an additional K step, enhanced variable fluorescence (VK) and degree of damage to the OEC (WK) during salinity, and indicates damage of OEC at electron donor side of photosystem II (PSII). The OEC intact within PSII was a primary damage center during salinity which inhibited electron transport process that resulted in a huge loss of maximum quantum yield of PSII (Fv/Fm), but a significant recovery in photosynthetic apparatus was observed after exogenous application of manganese. Structural and functional integrity of the photosynthetic apparatus was recovered up to a certain extent after exogenous application of Mn. Findings from this study should help to understand the basic knowledge of photosynthetic apparatus efficiency in response to damage caused by exposure to seawater. Outcomes of this study will be used to mitigate salinity problem with Mn supplement for growth and development of crops.

Spinach, a nutrient-dense, green-leafy vegetable, is a rich source of carotenoid and chlorophyll bioactives. While the content of bioactives is known to vary with the genotype, variation in bioaccessibility is unknown. Bioaccessibility was explored in 71 greenhouse-grown spinach genotypes in fall and spring 2018/2019. Spinach was phenotyped for its greenness, leaf texture, leaf shape, and SPAD chlorophyll content. Postharvest, spinach was washed, blanched, and homogenized prior to assessment of bioactive bioaccessibility using a novel high-throughput in vitro digestion model followed by high-performance liquid chromatography with a photodiode array detector analysis. There was a significant variation in the bioaccessible content for all bioactives (p < 0.05), except for chlorophyll b (p = 0.063) in spring-grown spinach. The correlation coefficients of bioaccessible contents between seasons reveal that lutein (r = 0.52) and β-carotene (r = 0.55) were correlated to a greater extent than chlorophyll a (r = 0.38) and chlorophyll b (r = 0.19). The results suggest that carotenoid and chlorophyll bioaccessible contents may vary based on spinach genotypes and may be stable across seasons.

The article presents experimental results of a comparative assessment of the pigment complex of the leaves of the Englishoak growing in the protective forest strips of the Stone Steppe. It is shown that the maximum level of chlorophyll a content ischaracteristic of the leaves of oak trees of protective forest strip No. 131 and is equal to 3.02±0.09 mg/g a.d.m. In oak leaves offorest strip No. 226, the content of this pigment is 9.6% lower. It was found that there are no statistically significant differencesin the average content of chlorophyll b in the leaves of oak trees of the studied forest strips. It is shown that the content ofphotosynthetic pigments is an environmentally dependent indicator reflecting the vital state of plants, the nature of the ongoingphysiological processes, as well as the direction of adaptive reactions when exposed to stress factors., В статье представлены экспериментальные результаты сравнительной оценки пигментного комплекса листьевдуба черешчатого, произрастающего в полезащитных лесных полосах Каменной Степи. Показано, что максимальныйуровень содержания хлорофилла а характерен для листьев деревьев дуба полезащитной лесополосы №131 и равен3.02±0.09 мг/г а.с.в. В листьях дуба лесополосы №226 содержание данного пигмента на 9.6% ниже. Установлено, чтопо среднему содержанию хлорофилла b в листьях деревьев дуба исследуемых лесных полос статистическидостоверных различий нет. Показано, что содержание фотосинтетических пигментов является является экологическизависимым показателем, отражающим жизненное состояние растений, характер протекающих физиологическихпроцессов, а также направленность адаптивных реакций при воздействии стрессовых факторов., Journal of Agriculture and Environment, Выпуск 1 (21) 2022, Page 18

Plasma activated water (PAW) has proven to be a promising alternative for the decontamination of rocket leaves. The impact of PAW on the volatile profile, phytosterols, and pigment content of rocket leaves was studied. Leaves were treated by PAW at different times (2, 5, 10, and 20 min). Compounds of the headspace were detected and quantified using GC–MS analysis. A total of 52 volatile organic compounds of different chemical classes were identified. Glucosinolate hydrolysis products are the major chemical class. PAW application induced some chemical modifications in the volatile compounds. Changes in the content of the major compounds varied with the increase or decrease in the treatment time. However, PAW-10 and -2 were grouped closely to the control. A significant decrease in the content of β-sitosterol and campesterol was observed after PAW treatment, except for PAW-10, which showed a non-significant reduction in both compounds. A significant increase in β carotene, luteolin, and chlorophyll b was observed after the shortest treatment time of PAW-2. A reduction in chlorophyll content was also observed, which is significant only at longer treatment, or PAW-20. Overall, PAW has proven to be a safe alternative for rocket decontamination.

The lisianthus culture is demanded to produce cut flowers and pot vases, grown in a greenhouse using advanced techniques. The present study aimed to evaluate the pigments of different lisianthus cultivars in different photoselective shade nets. The cultivars Flare Deep Rose (pink), Echo Blue BL (purple) and Allemande White BI (white) were cultivated under light-diffusing polyethylene film cover and blue and red color photoselective nets with a shading capacity of 30%, in addition to the control treatment, without the use of the net. The results showed higher values of chlorophyll b and total in the red photoselective net, independent of the cultivar. Leaf colorimetry showed the most intense shade of green was from the cultivar Echo Blue BL. On the other hand, the control showed more intensity, with no significant difference in the leaf green intensity on the blue and red shade nets. In the petals, the cultivar Echo Blue BL showed a more intense blue shade in the red net, however low grade of anthocyanin than in the blue one. In the anthocyanin pigment, this cultivar had lower levels in the treatment of the red net. The results indicate that the use of photoselective shade nets in the culture of lisianthus changes the content of the pigments studied, in varying intensity, depending on the cultivar. Resumo O cultivo do lisianthus destaca-se na cadeia produtiva da floricultura como uma espécie destinada à produção de flores de corte e em vaso, cultivada em casa de vegetação empregando técnicas avançadas de produção. O objetivo do presente trabalho foi avaliar os pigmentos vegetais de diferentes cultivares de lisianthus sob diferentes telas foto seletivas. As cultivares Flare Deep Rose (rosa), Echo Blue BL (roxa) e Allemande White BI (branca) foram cultivadas com cobertura de filme de polietileno difusor de luz e telas foto seletivas das colorações, azul e vermelha, com capacidade de sombreamento de 30%, além do tratamento controle, sem o uso de tela. Os resultados obtidos demonstraram maiores valores de clorofila b e total em tela foto seletiva vermelha, independentemente do cultivar. Na colorimetria das folhas, a tonalidade de verde mais intensa foi do cultivar Echo Blue BL. Por outro lado, o controle apresentou tonalidade mais intensa, não ocorrendo diferença significativa na intensidade do verde das folhas nas telas azul e vermelha. No telado vermelho, as pétalas da variedade Echo Blue BL apresentaram tonalidade de azul mais intensa, porém menores teores de antocianina. Os resultados indicam que o uso de telas foto seletivas na cultura de lisianthus altera o teor dos pigmentos estudados, em intensidade variável, dependendo do cultivar.

The origin of chlorophyll b deficiency is a mutation (ch1) in chlorophyllide a oxygenase (CAO), the enzyme responsible for Chl b synthesis. Regulation of Chl b synthesis is essential for understanding the mechanism of plant acclimation to various conditions. Therefore, the main aim of this study was to find the strategy in plants for compensation of low chlorophyll content by characterizing and comparing the performance and spectral properties of the photosynthetic apparatus related to the lipid and protein composition in four selected Arabidopsis ch1 mutants and two Arabidopsis ecotypes. Mutation in different loci of the CAO gene, viz., NW41, ch1.1, ch1.2 and ch1.3, manifested itself in a distinct chlorina phenotype, pigment and photosynthetic protein composition. Changes in the CAO mRNA levels and chlorophyllide a (Chlide a) content in ecotypes and ch1 mutants indicated their significant role in the adjustment mechanism of the photosynthetic apparatus to low-light conditions. Exposure of mutants with a lower chlorophyll b content to short-term (1LL) and long-term low-light stress (10LL) enabled showing a shift in the structure of the PSI and PSII complexes via spectral analysis and the thylakoid composition studies. We demonstrated that both ecotypes, Col-1 and Ler-0, reacted to high-light (HL) conditions in a way remarkably resembling the response of ch1 mutants to normal (NL) conditions. We also presented possible ways of regulating the conversion of chlorophyll a to b depending on the type of light stress conditions.

The moss Physcomitrium patens diverged from green algae shortly after the colonization of land by ancient plants. This colonization posed new environmental challenges which drove evolutionary processes. The photosynthetic machinery of modern flowering plants is adapted to the high light conditions on land. Red shifted Lhca4 antennae are present in the photosystem I light harvesting complex of many green lineage plants but absent from P. patens. The Cryo-EM structure of the P. patens photosystem I light harvesting complex I supercomplex (PSI-LHCI) at 2.8 Å reveals that Lhca4 is replaced by a unique Lhca2 paralogue in moss. This PSI-LHCI supercomplex also retains the PsaM subunit, present in cyanobacteria and several algal species but lost in higher plants, and the PsaO subunit responsible for binding light harvesting complex II. The blue shifted Lhca2 paralogue and chlorophyll b enrichment relative to higher plants make the P. patens PSI-LHCI spectroscopically unique among other green lineage supercomplexes. Overall, the structure represents an evolutionary intermediate PSI with the crescent shaped LHCI common in higher plants and contains a unique Lhca2 paralogue which facilitates the mosses adaptation to low light niches.

Arbuscular mycorrhizal fungi (AMF) inoculation and biochar amendment has been reported to improve the growth of several crop plant, however, their role in stress amelioration individually as well as in combination has not been worked out. Limited information is available about the synergistic use of biochar and Arbuscular Mycorrhizal Fungi (AMF). Here, we investigated the synergistic effect of biochar and AMF on plant development, root architecture, the physiological performance of fenugreek (Trigonella foenum-graecum), and soil enzymatic activities. Biochar and AMF were shown to have a considerable effect on plant height, according to the data (53.3 and 66.6%, respectively), leaf number (22.5 and 45.1%), total root length (19.8 and 40.1%), root volume (32.1 and 71.4%), chlorophyll a content (26.0 and 17.8%), chlorophyll b content (50.0 and 28.9%), total chlorophyll content (30.0 and 18.1%), and carotenoid content (60.0 and 48.0%) over the control treatment. There was a considerable increase in plant height when biochar and AMF were combined together by 80.9%, total root length by 68.9%, projected area by 48.7%, root surface area by 34.4%, root volume by 78.5%, chlorophyll a content by 34.2%, chlorophyll b content by 68.4%, total chlorophyll content by 44.5%, and carotenoid content by 84.0% compared to the control. Our results recommend that the combination of biochar and AMF is advantageous in fenugreek growth, microbial biomass, and soil enzyme activities.

Plant species exhibiting heavy metal tolerance are instrumental in phytoremediation of metalliferous sites. Most of the time, variations in plant functional traits (PFTs) are overlooked while identifying hyperaccumulators. However, investigating morphological, physiological, and phenological variations can contribute to our knowledge about stress tolerance, and aid in identifying potential hyperaccumulators. In the present study, we investigated variation in morpho-functional traits in Solanum nigrum, a known hyperaccumulator, under lead (Pb) stress. Twenty-one PFTs including 9 above-ground (leaf count, leaf area, specific leaf area, leaf dry matter content, leaf thickness, leaf dry mass, shoot length, stem dry mass, stem diameter), 3 below-ground (root length, root dry mass, and root diameter), 4 reproductive (flower bud count, fruit count, flower count, and fruit dry mass), and 5 photosynthetic traits (total chlorophyll, total carotenoid, chlorophyll a, chlorophyll b, and photosynthetic efficiency) under varying Pb concentrations (500–2000 mg kg−1) were assessed. Pillai’s trace test (MANOVA) depicted significant variations in above-ground, below-ground, and photosynthetic traits, whereas reproductive traits did not vary significantly with progressive metal concentration. However, most of the studied traits except flower count, fruit dry mass, and chlorophyll b varied significantly under Pb stress. The study depicts that enhanced PFT’s plasticity enables S. nigrum to grow in Pb-contaminated soil effectively without impacting plant fitness. Plasticity of morpho-functional traits, therefore, establishes itself as a resourceful approach in successful identification of phytoremediation capacity of a plant.

The aim of this work was to study the evolution of fruit size and weight together with the soluble solid and total titratable acidity contents during development of Hexachlamys edulis fruit. Also, the patterns of accumulation of chlorophylls, carotenoids, phenols and antioxidant activity were analysed to define the optimal time for harvesting to obtain maximum nutraceutical characteristics. Fruits were harvested from H. edulis plants growing at the experimental field of the University of Moron (Moreno, Buenos Aires, 34°35'4.98" SL, 58°48'52.09" WL, 14 m.a.s.l.). Fresh fruit weight was significantly higher in Medium ripe, Ripe and Overripe fruits (40.1, 39.6 and 38.5 g, respectively) than in Unripe fruits (19.5 g). Soluble solids/total titratable acidity was significantly higher in Overripe fruits (7.3) than in Unripe, Medium ripe and Ripe fruits (3.7 to 4.5). Total polyphenols were maximum in Unripe fruits (905.8 mg tannic acid/100 g fresh fruit weight) decreasing during the fruit development (426.2 to 130.4 mg tannic acid/100 g fresh fruit weight). Also, DPPH radical scavenging activity was significantly higher in Unripe fruits (75.7%) compared with Medium ripe, Ripe and Overripe fruits (64.1 to 17.0%). Positive and significant correlations were observed between total polyphenol content and DPPH radical scavenging activity at each extract concentration (r= 0.74, 0.87, 0.74 and 0.60 for 1.25; 2.50; 5.00 and 12.50 mg/mL, respectively). Total carotenoid content increased during fruit development while at the same time decreased chlorophyll content. Chlorophyll b is the main chlorophyll found. Chromatographic analysis showed that lutein is the main carotenoid found in H. edulis fruits, followed by β-cryptoxanthin and β-carotene. As shown by the chromatograms at 280 nm, the concentration of biophenols and the complexity of the biophenol profile decreases during fruit development. Levels of polyphenols and pigments together with the antioxidant activity allow us to consider H. edulis fruit as a functional food.

Waterlogging severely affects global agricultural production. Clarifying the regulatory mechanism of grapevine in response to waterlogging stress will help to improve the waterlogging tolerance of grapevine. In the present study, the physiological and proteomic responses of SO4 grapevine rootstock to different waterlogging tolerances were comparatively assayed. The results showed that the activities of SOD and POD first increased and then decreased, while the change trend of CAT and APX activities was the opposite. In addition, the MDA and H2O2 contents increased after waterlogging treatment, but the chlorophyll a and chlorophyll b contents decreased. A total of 5,578 grapevine proteins were identified by the use of the tandem mass tag (TMT) labeling technique. Among them, 214 (103 and 111 whose expression was upregulated and downregulated, respectively), 314 (129 and 185 whose expression was upregulated and downregulated, respectively), and 529 (248 and 281 whose expression was upregulated and downregulated, respectively) differentially expressed proteins (DEPs) were identified in T0d vs. T10d, T10d vs. T20d, and T0d vs. T20d comparison groups, respectively. Enrichment analysis showed that these DEPs were mainly involved in glutathione metabolism, carbon fixation, amino sugar and nucleotide sugar metabolism, biosynthesis of amino acids, photosynthesis, carbon metabolism, starch, and sucrose metabolism, galactose metabolism, protein processing and ribosomes. To further verify the proteomic data, the expression of corresponding genes that encode eight DEPs was confirmed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). The results of this study presented an important step toward understanding the resistance mechanisms of grapevine in response to waterlogging stress at the proteome level.

BackgroundToday, stress moderators are employed to mitigate crop loss due to the adverse effects of environmental stress. The current research aimed to investigate the impacts of time and stress moderator types on agro-physiological responses of cotton on conventional and double-cropping systems during 2017 and 2018 under saline conditions. A split-plot factorial experiment was carried out in a randomized complete block design with three replications. Cultivation system [conventional (recommended planting date) and double-cropping systems (sowing after harvest of wheat)] were considered as the main plots, and stress moderator type at four levels [water control, 2 mmol·L–1Salicylic acid (SA), 100 mmol·L–1Glycine betaine (GB), and 100 μmol·L–1sodium nitroprusside (SNP)] and application time (flowering and flowering + bolling stages) were regarded as subplots.ResultsPlant height, reproductive branch number, the number of bolls, 10-boll weight, 1 000-seed weight, biological yield, seed cotton yield, lint yield, chlorophyll a, chlorophyll b, carotenoids, total chlorophyll, sodium, potassium, and proline content were less in double-cropping system comparing with conventional system. Spraying with the stress moderators alleviated soil salinity effects on yield, yield components, and biochemical traits of cotton. SNP spraying led to maximum plant height, branch number, the number of bolls per plant, 10-boll weight and seed cotton yield. SA spraying yielded the highest 1 000-seed weight, biological yield, lint percentage and lint yield. The highest chlorophyll a, chlorophyll b, carotenoids, and total chlorophyll content resulted from SNP spraying. Yield, yield components, and biochemical traits did not respond to the stress moderator types in double-cropping system. However, the highest chlorophyll a, carotenoids, proline content, the number of bolls per plant, and seed cotton yield resulted from SNP spraying in conventional system. No statistically significant differences were observed between spraying with SNP and SA in most studied traits.ConclusionsThe results suggest that the optimum cotton planting time and SNP spraying could be recommended for producing the most suitable yield under saline conditions.HighlightsExternal application of stress modulators increases salinity stress tolerance.Spraying with sodium nitroprusside has more moderating effect.Agro-physiological response of cotton to moderators is stronger in early sowing.Maximum seed cotton yield was achieved at early sowing and spraying sodium nitroprusside.Delayed cultivation reduces cotton yield.

The characteristic plants of understory environments show varied colors in their leaves, called variegations. These tend to regulate, through their concentrations of leaf pigments, their photosynthetic processes. The objective of this research was to carry out a comparative analysis of leaf pigment concentrations and chlorophyll a fluorescence parameters in four species of variegated plants, Fittonia albivenis, Alternanthera ficoidea, Tradescantia spathacea and Hypoestes phyllostachya, as well as the control species, Jasminum mesnyi, and Tradescantia pallida. To determine which are most suitable for environments with high and low light intensities. The analysis of leaf pigments were carried out by spectrophotometry, and to analyze the fluorescence emission of chlorophyll-a PAM-2500 fluorometer was used, whose parameters were calculated from the JIP test. The chlorophyll a levels ranged from 27.67 to 110.88 (μg mL-1 gMF-1), those of chlorophyll b ranged from 10.29 to 40.64 (μg mL-1 gMF-1). Carotenoid titers ranged from 2.6275 to 26.1925 (μg mL-1 gMF-1), and anthocyanins ranged from 0 to 2.25679 (μg mL-1 gMF-1), with the highest titers occurring for the control species J. mesnyi and the variegated F. albivenis. The fluorescence parameters differed statistically among the variegated plant species concerning the controls. We conclude that the species T. spathacea presents better adaptation to environments with high levels of light radiation. In environments with more significant variation in light radiation, the species variegated H. phyllostachya and A. ficoidea will develop better. Finally, the species variegated F. albivenis must be maintained in environments with low levels of light radiation.

In the present investigation, we study the effect of Bacillus thuringiensis MH161336 (106–8 CFU/cm3), silicon (25 mL L−1), and carrot extract (75 mL L−1) as seed primers, individually or in combination, on morphological, physio-biochemical and yield components of drought-stressed pea plants (Master B) during 2019/2020 and 2020/2021 seasons. Our results indicated that drought causes a remarkable reduction in plant height, leaf area, number of leaves per plant, and number of flowers per plant in stressed pea plants during two seasons. Likewise, number of pods, pod length, seeds weight of 10 dried plants, and dry weight of 100 seeds were decreased significantly in drought-stressed pea plants. Nevertheless, seed priming with the individual treatments or in combination boosted the morphological, physio-biochemical, and yield characters of pea plants. The best results were obtained with the Bacillus thuringiensis + carrot extract treatment, which led to a remarkable increase in the number of leaves per plant, leaf area, plant height, and number of flowers per plant in stressed pea plants in both seasons. Moreover, pod length, number of seeds per pod, seeds weight of 10 dried plants, and dry weight of 100 seeds were significantly increased as well. Bacillus thuringiensis + carrot extract treatment led to improved biochemical and physiological characters, such as relative water content, chlorophyll a, chlorophyll b, regulated the up-regulation of antioxidant enzymes, increased seed yield, and decreased lipid peroxidation and reactive oxygen species, mainly superoxide and hydrogen peroxide, in drought-stressed pea plants.

Anthropogenic activities are the foremost reason of metal pollution in soils of the cultivated areas, resulting abnormal physiochemical processes in plants. Among metals contaminants, cadmium (Cd) is one of the most injurious contaminants that deleteriously affect physiological activities, growth and yield of the crop plants. Keeping in view the stress mitigation potential of titanium dioxide (TiO2), the existing research work was premeditated to inspect the beneficial role of seed priming with titanium dioxide nanoparticles (TiO2-NPs) on biochemical, morphological and physiological characteristics of Coriandrum sativum L. (coriander) plants under Cd stress. For this purpose, C. sativum seeds were primed with 0, 40, 80 and 160 mg L−1 TiO2-NPs. Cadmium stress triggered a significant decrease in chlorophyll a content (49%), chlorophyll b content (44%), photosynthetic rate (62%) and plant growth (51%) as compared with control. Tanium dioxide nanoparticles treated seedlings exhibited reduced Cd contents besides improved agronomic traits (seedlings biomass, number of seeds and yield). The TiO2-NPs treatment declined the magnitude of EL and MDA by 1.5 fold and 1.71 fold, respectively. Furthermore, TiO2-NPs diminished oxidative injuries in plants exposed to Cd stress. Additionally, TiO2-NPs enhanced the biosynthesis of osmatic regulators (proline) by 47% which helped in the mitigation of Cd persuaded toxicity in plants. Briefly, treatment of 80 mg L−1 TiO2-NPs perhaps ameliorates the deleterious influence of Cd stress and enhance the yield of coriander.

Pouteria gardneriana Radlk (guapeva) is a tree native to the Brazilian Cerrado with economic, ecological, and biotechnological importance. Guapeva yield is limited mainly by the seeds recalcitrance, that can be overcome by micropropagation technique and effective acclimatization. The objective of this study was to investigate the role of in vitro rooting and inoculation of plant growth–promoting bacteria (PPGPB) during acclimatization of micropropagated P. gardneriana plantlets. In the first bioassay, the presence of roots in the plantlets resulted in higher values of biometric features, such as leaf area, numbers of leaves and secondary roots, nodal segments, fresh and dry weights of leaves; when compared to plantlets without roots. Roots well established also resulted in higher levels of chlorophyll a, chlorophyll b, and total chlorophyll and a higher photosynthetic rate in micropropagated P. gardneriana plantlets. Fr the second biassay, the PGPB inoculation was done with bacteria to solubilize phosphate and phytohormone production, in addition to low pathogenic potential in the Galeria mellonella larva animal model. The inoculation of the Bac109 and BP323EB consortium in plantlets rooted in vitro had a positive effect on the root length of the plantlets during the acclimatization phase, which may favor the long-term development of the plant. This study demonstrated that both in vitro rooting and inoculation of a bacterial consortium may contribute to the growth of P. gardneriana during acclimatization, leading to higher productivity and seedling quality.

DOI: 10.15835/nbha49312063 Seed priming has proved to be an effective method in imparting stress tolerance to plants using natural and/or synthetic compounds to treat the seeds before germination. The present study was designed to investigate the physiological mechanism of seed priming with ZnSO4 (osmopriming) and distilled water (hydropriming) on sugar beet genotypes (‘Shokofa’, ‘Sina’, ‘Paya’, ‘Turbata’, and ‘Aria’) germination indices, seedling growth parameters, and biochemical properties under salinity stress (0, 2, 5, and 12 dS/m NaCl). A significant reduction in germination percentage (33.23%), germination rate (77.2%), chlorophyll a, b, and total contents (43.9, 31.9, and 39.9%, respectively) while, a significant increase in radical, plumule, and seedling length (57.1, 44.4, and 51.2%, respectively), seedling vigour index (48.9%), superoxide dismutase activity (61.3%), proline (54.0%) and sugar (56.3%) contents were achieved at 12 dS/m NaCl in compared to the control treatment. Seed hydropriming and osmopriming caused significant improvements in photosynthetic pigments, antioxidant enzyme activity, and proline content reflected in high germination percentage and rate as well as seedling vigour index and reduced mean germination time under salinity. ‘Paya’ and ‘Aria’ genotypes had a superiority according to the germination percentage and seedling vigour index, respectively. The hydropriming of ‘Paya’ genotype resulted in the highest germination percentage (95%) under high level of salinity (12 dS/m) which 11.84% increase compared to the control treatment. Hydropriming of ‘Sina’ seeds showed the highest chlorophyll a and total, and carotenoids under non-stress conditions (22.89, 31.65, and 2116.6 µg/g FW). Also, hydropriming by increases chlorophyll b content led to the modulation of the negative effects of high salinity stress (12 dS/m). In conclusion, different seed priming treatments in sugar beet seeds improved the salinity tolerance by physiological characteristics nonetheless hydropriming was the most effective treatment to get higher germination indices in ‘Paya’ and ‘Aria’ genotypes.

Koelreuteria integrifoliola, an important ornamental plant, has interference effect on the turf grass. However, the mechanisms of its allelopathy to plants has not been fully elucidated. Here, the allelopathic effects of leaf aqueous extract of K. integrifoliola on the growth, endogenous hormone contents and ultrastructure of Lolium perenne Lam seedlings were investigated. Leaf aqueous extract of K. integrifoliola at different concentrations (25.00, 50.00 and 100.00 mg mL−1) significantly reduced the growth (in terms of dry weight), chlorophyll b, total chlorophyll and carotenoids contents of L. perenne. The results also showed the decline in indole acetic acid (IAA) and gibberellic acid (GA3) contents, and the increase in abscisic acid (ABA) after extract treatment (50.00 and 100.00 mg mL−1). In addition, the (IAA + GA3)/ABA ratios in root and leaf decreased with the increase of extract concentrations. Upon exposure to extracts (50.00 and 100.00 mg mL−1), L. perenne mesophyll cell showed structural abnormalities, mostly including chloroplast distribution, destruction of chloroplast membrane and thylakoid membrane, increment of plastoglobuli number, dissolution of mitochondrial membrane and disappearance of the internal ridge. Furthermore, the chloroplast number and chloroplast volume in L. perenne mesophyll cell showed a concentration-dependent decline exposed to extracts. Thus, the changes of endogenous hormones contents and their ratios, the ultrastructure changes of mesophyll cells caused by the K. integrifoliola leaf aqueous extracts are partly responsible for allelopathic inhibition of receptor plants.

A trial was conducted to find out the best treatment combination for an experiment “Effect of integrated manuring and growth regulators on vegetative growth and flowering of pineapple” with an objective to get high, uniform vegetative growth and flowering in pineapple by integrated application of manure and growth regulators. The result revealed that 75% of recommended NPK + 25% of N through organic recycling with vermicompost along with NAA@10ppm, GA3@50ppm Ethrel@25ppm Perform best treatment combination with respect to physiological characters like, number of leaves per plant (49.19) number of leaves produced (3.96 per plant per month), chlorophyll a content (0.385 mg/g fresh leaf), chlorophyll b content (0.160 mg/g fresh leaf) total chlorophyll content (0.552 mg/g fresh leaf), percentage of flowering (92.76 %), and maximum plant height (82.28cm), length of D- leaf (76.50cm), width of D-leaf (6.14cm), with, leaf area (273.17cm2). Flowering character like minimum number of days to flower initiation (42.84 days), minimum number of days required from flower initiation to fruit maturity (108.25 days) where significant variation found in 75% of recommended NPK + 25% of N through organic recycling with vermicompost along with NAA@10ppm.

How the NPs effect the growth and physiological response like the release of organic acids along the root exudates is largely unknown yet. In this study, the effects of titanium dioxide (TiO2) and silicon dioxide (SiO2) nanoparticles (NPs) treatments (1000 mg/L) on maize seedlings for 6 days were examined. Plant biomass, pigment, malondialdehyde (MDA), reactive oxygen species (ROS) production, and contents of organic acids in root exudates were analyzed. SiO2 NPs significantly reduced (p 0.05) in chlorophyll a content compared to the CK, while chlorophyll b increased by 28.9% (p

The physiological and biochemical changes in the green macroalga Ulva pertusa during the progression of sporulation have been characterized. The transition from the vegetative to the sporulation stage was accompanied by an increase in chlorophyll a (Chl a), chlorophyll b (Chl b), and carotenoid content, as well as an increase in DPPH scavenging and responsiveness to diphenylamine. However, oxygen evolution and maximum electron transport rate decreased. The discrepancy between photosynthetic performance and pigment content might relate to the self-shading of spores within a sporangium. Spore-forming U. pertusa thalli were low-light-adapted, due to an increase in the number of photosynthetic units. Decreased electron transport during sporulation might trigger sporulation, as for some cyanobacteria and other Ulva spp., via oxidization of the plastoquinone pool and cyclic phosphorylation, thus producing ATP to generate carbon and nitrogen skeletons required for spores. It is thus concluded that carotenoids function both in spore initiation and/or maturation and in their photoprotection.

The study was conducted to investigate the effects of foliar-intervention of nano-TiO2 on Cd toxicity in cowpea plants. Cowpea plants were exposed to Cd toxicity at 10 mg/kg soil for 21 days and afterwards, subjected to six episodes of foliar application of nano-TiO2 intervention. Results showed that foliar-applied nano-TiO2 significantly promoted chlorophyll b and total chlorophyll contents after Cd stress as compared to Cd-stressed plants without the intervention. Interestingly, Cd contents of roots, shoots and grains were significantly reduced (p

This study aimed to investigate the effect of iron toxicity in cowpea using physiological and biochemical responses of selected accessions. Fifteen accessions of cowpea were exposed to two treatments of iron using FeSO4 solution (100 mg l-1 and 400 mg l-1) and distilled water at pH 6.2 as control. The results showed that there was a general reduction in germination morphology; germination percentage among the 400 mg l-1 Fe-treated accessions. Seed mortality rates were significantly higher among the 400 mg l-1Fe-treated accessions (> 35 %). Water imbibition capacity and relative mass gained were higher for Fe-treated accessions. Furthermore, significant increase in the total sugar and percentage utilization of sugars was accompanied by an insignificant decrease in chlorophyll a, a significant decrease in chlorophyll b contents and the persistence of foliar chlorosis, among the 400 mg l-1 Fe-treated accessions. MDA levels were significantly increased while proline remained unchanged, mean SOD activity was insignificantly increased, whereas Cat decreased among the 400 mg l-1 Fe-treated accessions. Documentation of these observable changes in physiological and biochemical parameters will be useful in understanding the impact of elevated iron concentrations on the cultivation of cowpea accessions in soils associated with ferruginous ultisols.

Photosynthetic pigments analysis has become a standard tool in ecological and physiological studies of photosynthetic organisms. With numerous methods previously published, there is no one ideal protocol that could satisfy all the research needs. Therefore, regarding the purpose of HPLC pigment analyses, a suitable method should be chosen. In this study, two C18 columns (i.e., LiChrospher 100 RP18e and Spherisorb ODS2) and three sets of eluents (based on acetone, acetonitrile, methanol, and water) were used to develop three separation protocols. They were then examined with respect to their resolution and sensitivity, by analyzing pigment extracts obtained from 10 cyanobacterial and algal cultures and two types of environmental samples, i.e. phytoplankton and microphytobenthos. All the protocols provided highly repeatable results and allowed for the separation of all taxonomically most relevant chlorophylls and carotenoids. They had similar resolution and sensitivity. The Syst1 method was the shortest, while Syst2 had better resolution of pigments in the middle part of the protocol when most of the diagnostic pigments are separated (i.e., alloxanthin, diatoxanthin, lutein, chlorophyll b). Syst3, on the other hand, enabled distinguishing the highest number of pigments, including their derivatives and degradation products. The results showed that all protocols may be used for routine analysis of cyanobacterial and algal pigments in various sample types.

Two field experiments were conducted during two seasons of 2017 and 2018 to evaluate the effect of both bio-fertilizer (inoculated or uninoculated) and selenium (Se) spray at 0.5, and 10 ppm on vegetative growth, pigments, yield and quality of potato plants. The results indicated that, vegetative growth characters (number of leaves, plant height, plant fresh weight, plant dry weight, leaf area and leaf pigments (chlorophyll a, chlorophyll b and chlorophyll a and b were significantly increased with Bio-fertilizers (Halex-2, and High rate of Se (10 ppm), in both seasons. Plant yield of tuber, number of tubers/plant, average tuber weight and tuber yield/Fed and (tuber content of starch and protein), generally, seemed to be increased with the Bio-fertilizer (Halex-2) and high rate of Se, in both growing seasons. The interaction between Bio-fertilizer (Halex-2) and Se reflected positive effects on the all studied quantitative and qualitative characters of potato plants.

The present study was carried out to evaluate the biochemical changes occurring in infected and non infected leaves of tomato with Alternaria solani. Various biochemical constituents were studied viz., chlorophyll content (chlorophyll a and chlorophyll b), total sugars (reducing and non reducing sugar), total phenol content and total soluble protein. Results revealed that infected plants show severe necrosis and there is sudden decline in chlorophyll content (chlorophyll a and chlorophyll b) and in amount of total soluble sugar (reducing and non reducing sugar) and increase in protein and phenol content in infected plants. The result indicate that pathogen Alternaria solani causes severe alteration in biochemical constitutes of tomato plant that directly or indirectly reduce the resistance or weakens the defense response of tomato against virulent pathogen.

In the last decade, the cyanobacterium Spirulina has gained a high commercial interest as a food supplement, mainly due to its high protein content as well as high amounts of pigments, such as carotenoids, chlorophylls and phycocyanins. In particular, phycocyanin has been widely considered as a precious food-dye because of its protein-based structure and the rare intense-blue color. Different strategies were developed for the isolation and purification of phycocyanin. The main drawback of such processes is that carotenoids and chlorophylls are generally wasted together with the residual biomass. In this study, a different approach is proposed, suggesting an integrated pigment extraction chain. The body of the strategy involves two consecutive steps of the supercritical-CO2 extraction of carotenoids and chlorophylls, before phycocianin extraction. The total carotenoid, chlorophyll a and chlorophyll b contents in the extracts were equal to 3.5 ± 0.2 mg g−1, 5.7 ± 0.2 mg g−1 and 3.4 ± 0.3 mg g−1, respectively (by dry Spirulina weight). The biomass residue, exhausted in terms of carotenoids and chlorophylls, was then extracted in water to yield phycocyanin. Consecutive steps were developed in order to ehance the phycocyanin purity, including electrocoagulation, dialysis and protein salting-out. These processes yielded 250 mg g−1 of phycocyanin (by dry Spirulina weight). A potentially scalable strategy to obtain the blue pigment with high purity (A620/A280 = 2.2) was developed. The practical application of the extracted blue phycocyanin pigment as a cotton-based tissue colorant was also experimented.

All algae documented so far are of unknown origin. Here, we provide a taxonomic description of the first origin-known alga TDX16-DE that arises from the Chroococcidiopsis-like endosymbiotic cyanobacterium TDX16 by de novo organelle biogenesis after acquiring its green algal host Haematococcus pluvialis’s DNA. TDX16-DE is spherical or oval, with a diameter of 2.0-3.6 μm, containing typical chlorophyte pigments of chlorophyll a, chlorophyll b and lutein and reproducing by autosporulation, whose 18S rRNA gene sequence shows the highest similarity of 99.7% to that of Chlorella vulgaris. However, TDX16-DE is only about half the size of C. vulgaris and structurally similar to C. vulgaris only in having a chloroplast-localized pyrenoid, but differs from C. vulgaris in that 1) it possesses a double-membraned cytoplasmic envelope but lacks endoplasmic reticulum and Golgi apparatus; and 2) its nucleus is enclosed by two sets of envelopes (four unit membranes). Therefore, based on these characters and the cyanobacterial origin, we describe TDX16-DE as a new genus and species, Chroococcidiorella tianjinensis gen. et sp. nov., which sets the basis for multidisciplinary research.

Salt stress causes nutritional imbalance and ion toxicity which affects wheat growth and production. A population of recombinant inbred lines (RILs) were developed by crossing Pasban90 (salt tolerant) and Frontana (salt suceptible) for identification of quantitative trait loci (QTLs) for physiological traits including relative water content, membrane stability index, water potential, osmotic potential, total chlorophyll content, chlorophyll a, chlorophyll b and biochemical traits including proline contents, superoxide dismutase, sodium content, potassium content, chloride content and sodium/potassium ratio by tagging 202 polymorphic simple sequence repeats (SSR) markers. Linkage map of RILs comprised of 21 linkage group covering A, B and D genome for tagging and maped a total of 60 QTLs with major and minor effect. B genome contributed to the highest number of QTLs under salt stress condition. Xgwm70 and Xbarc361 mapped on chromosome 6B was linked with Total chlorophyll, water potential and sodium content. The increasing allele for all these QTLs were advanced from parent Pasban90. Current study showed that Genome B and D had more potentially active genes conferring plant tolerance against salinity stress which may be exploited for marker assisted selection to breed salinity tolerant high yielding wheat varieties. Keywords: Genome, Plant attributes, QTLs, Wheat, Salt stress

Cell immobilization on the magnetic nanoparticles (MNPs) and magnetic harvesting is a novel approach for microalgal cells separation. To date, the effect of these nanoparticles on microalgal cells was only studied over a short period of time. More studies are hence needed for a better understanding of the magnetic harvesting proposes or environmental concerns relating to long-term exposure to nanoparticles. In this study, the impact of various concentrations of MNPs on the microalgal cells growth and their metabolic status was investigated over 12 days. More than 60% reduction in mitochondrial activity and pigments (chlorophyll a, chlorophyll b, and carotenoids) content occurred during the first 6 days of exposure to ≥50 µg/mL nanoparticles. However, more than 50% growth inhibitory effect was seen at concentrations higher than 400 µg/mL. Exposure to MNPs gradually induced cellular adaptation and after about 6 days of exposure to stress generating concentrations (˂400 µg/mL) of IONs, microalgae could overcome the imposed damages. This work provides a better understanding regarding the environmental impact of MNPs and appropriate concentrations of these particles for future algal cells magnetic immobilization and harvesting., Graphical Abstract