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The discovery of new genes with novel functions is a major driver of adaptive evolutionary innovation in plants. Especially in woody plants, due to genome expansion, new genes evolve to regulate the processes of growth and development. In this study, we characterized the unique VeA transcription factor family in Populus alba × Populus glandulosa, which is associated with secondary metabolism. Twenty VeA genes were characterized systematically on their phylogeny, genomic distribution, gene structure and conserved motif, promoter binding site, and expression profiling. Furthermore, through ChIP-qPCR, Y1H, and effector-reporter assays, it was demonstrated that PagMYB128 directly regulated PagVeA3 to influence the biosynthesis of secondary metabolites. These results provide a basis for further elucidating the function of VeAs gene in poplar and its genetic regulation mechanism. [ABSTRACT FROM AUTHOR]

The photoperiod is a major environmental factor in flowering control. Water spinach flowering under the inductive short-day condition decreases the yield of vegetative tissues and the eating quality. To obtain an insight into the molecular mechanism of the photoperiod-dependent regulation of the flowering time in water spinach, we performed transcriptome sequencing on water spinach under long- and short-day conditions with eight time points. Our results indicated that there were 6615 circadian-rhythm-related genes under the long-day condition and 8691 under the short-day condition. The three key circadian-rhythm genes, IaCCA1, IaLHY, and IaTOC1, still maintained single copies and similar IaCCA1, IaLHY, and IaTOC1 feedback expression patterns, indicating the conservation of reverse feedback. In the photoperiod pathway, highly conserved GI genes were amplified into two copies (IaGI1 and IaGI2) in water spinach. The significant difference in the expression of the two genes indicates functional diversity. Although the photoperiod core gene FT was duplicated to three copies in water spinach, only IaFT1 was highly expressed and strongly responsive to the photoperiod and circadian rhythms, and the almost complete inhibition of IaFT1 in water spinach may be the reason why water spinach does not bloom, no matter how long it lasts under the long-day condition. Differing from other species (I. nil, I. triloba, I. trifida) of the Ipomoea genus that have three CO members, water spinach lacks one of them, and the other two CO genes (IaCO1 and IaCO2) encode only one CCT domain. In addition, through weighted correlation network analysis (WGCNA), some transcription factors closely related to the photoperiod pathway were obtained. This work provides valuable data for further in-depth analyses of the molecular regulation of the flowering time in water spinach and the Ipomoea genus. [ABSTRACT FROM AUTHOR]

Although we are in an era of enormous global commitments to ecological restoration (the UN Decade on ER; the Bonn Challenge), little attention has been paid to the importance of sustained commitment to individual restoration initiatives and few resources have been dedicated to monitoring, especially the long-term and broad-scale evaluations that would allow us to understand how basin-scale restoration can result in complex spatiotemporal patterns. Remote sensing offers a powerful tool for evaluating restoration initiatives focused on water management in arid regions, where changes in vegetation growth can be tracked visually with measures like the generalized difference vegetation index (GDVI). In this paper, we evaluate the Comprehensive Treatment Program of the Shiyang River Basin (CTSRB), a landscape restoration initiative in China's northwest, using a widely available remote sensing tool, showing how it can reveal the causes of fluctuating changes in restoration success. We focus on spatiotemporal variation, studying a time series from 2001 to 2020 using regression, trend, and stability analyses for six different divisions of the study region (the study area as a whole, the irrigated areas, the periphery of the irrigated regions, and the districts of Ba, Quanshan, and Hu) to evaluate the effects of the restoration initiative. The study period was divided into four equal-length phases based on the implementation timeline of the CTSRB, which includes one pre- and post-intervention interval and two stages of the CTSRB. We found that the CTSRB has played a positive role in the restoration of vegetation in the Minqin Basin, especially desert vegetation. However, the positive effects were not obvious in the first CTSRB period, which was characterized by a decline in vegetation growth likely caused by the strategy of "close the pumping-wells, transform the land", which reversed a greening trend caused by the unsustainable irrigation of wasteland prior to the project's initiation. During the second phase of the CTSRB, vegetation in the regions of "transform the land" gradually improved, and the growth of desert vegetation gradually improved and expanded as a result of more water flowing out of agricultural zones. The rate of vegetation recovery slowed down during the final phase of the CTSRB, and some areas even experienced a decline in the GDVI. Overall, our findings show that the CTSRB, by integrating water management and allowing for uninterrupted ecological restoration, drove complex regional changes in the GDVI, including successful restoration of desert vegetation. The spatiotemporal variable we observed underscores the importance of long-term commitment to arid land restoration initiatives and the importance of even longer-term monitoring using tools like remote sensing. [ABSTRACT FROM AUTHOR]

In addition to increasing grain yield, improving rice (Oryza sativa L.) quality has received increasing attention recently. The cooking and eating quality (CEQ) is an important indicator of rice quality. Chalkiness and floury endosperm have a significant impact on the CEQ of rice, resulting in noticeable changes. Due to the easily observable phenotype of floury endosperm, cloning single gene mutations that cause floury endosperm and indirectly evaluating changes in CEQs facilitates the exploration of minor genes controlling CEQ. In this study, a stable genetic allele variant of flo4, named flo4-7, was obtained through EMS mutagenesis. The flo4-7 allele variant carries the cyOsPPDKB mutation. flo4-7 showed a significant reduction in compound starch granules and a significant increase in single starch granules in endosperm cells, indicating the involvement of cyOsPPDKB in the synthesis of endosperm starch. Additionally, flo4-7 exhibited a significant decrease in gel consistency (GC) compared to the wild type. Through the analysis of GC data from 166 rice germplasm resources, a C-T variation in the 18th exon of cyOsPPDKB was found to be a crucial site, causing a significant difference in GC between indica and japonica rice. This locus can be used in the future to develop molecular markers for molecular marker-assisted breeding. This study provides a good research foundation for improving the CEQ of rice. [ABSTRACT FROM AUTHOR]

Besides increasing grain yield, improving rice (Oryza sativa L.) quality has been paid more and more attention recently. Cooking and eating quality (CEQ) is an important indicator of rice quality. Since CEQs are quantitative traits and challenging for measurement, efforts have mainly focused on two major genes, Wx and SSIIa. Chalkiness and floury endosperm significantly affect the eating quality of rice, leading to noticeable changes in CEQ. Due to the easily observable phenotype of floury endosperm, cloning single gene mutations that cause floury endosperm and evaluating changes in CEQs indirectly facilitate the exploration of the minor genes controlling CEQ. In this study, eight mutants with different degrees of floury endosperm, generated through ethylmethane sulfonate (EMS) mutagenesis, were analyzed. These mutants exhibited wide variation in starch morphology and CEQs. Particularly, the z2 mutant showed spherical starch granules significantly increased rapid visco analyzer (RVA) indexes and urea swelling, while the z4 mutant displayed extremely sharp starch granules and significantly decreased RVA indexes and urea swelling compared to the wild type. Additionally, these mutants still maintained correlations with certain RVA profiles, suggesting that the genes PUL, which affect these indexes, may not undergo mutation. Cloning these mutated genes in the future, especially in z2 and z4, will enhance the genetic network of rice eating quality and hold significant importance for molecular marker-assisted breeding to improve rice quality. [ABSTRACT FROM AUTHOR]

Crop productivity around the world is being seriously affected by adverse environmental conditions. High temperature (HT) stress has severely hampered plant growth, yield, and quality. Water spinach is a significant heat-resilient green leafy vegetable that can mitigate prolonged HT stress. However, the morphological, physiological, and biochemical alterations that occur in its response to heat stress remain unknown. In this study, the physiological response to HT stress in water spinach plants with different temperature (25-control, 30, 35, 40, 45 °C) tolerances was investigated. When plants were subjected to HT over a long period of time, their growth was stunted. The results showed that no significant difference was seen between the control (25 °C) and 30 °C for some traits (root shoot fresh weight, root morphological traits, and leaf gas exchanges parameters). Further, HT (35, 40, and 45 °C) stress significantly reduced the growth status, the gas exchange parameters, the pigment content, the photosystem function, and the root architecture system of water spinach. Conversely, HT stress considerably enhanced secondary metabolites in terms of total phenolics, flavonoids, soluble sugars, and anthocyanin content. Furthermore, heat stress remarkably increased the accumulation of reactive oxygen species (ROS) and caused cellular membrane damage. HT stress effectively altered the antioxidant defense system and caused oxidative damage. Generally, HT has an adverse effect on the enzyme activity of water spinach, leading to cell death. However, the current study found that temperatures ≥35 °C had an adverse effect on the growth of water spinach. Further research will be needed to examine the mechanism and the gene expression involved in the cell death that is caused by temperature stress in water spinach plants. [ABSTRACT FROM AUTHOR]

COVID-19, as a rampant health crisis, lies at the basis of fluctuating perceptions affecting decreased demand among travelers. Recent studies have witnessed a growth of interest in the interactions between tourists' behaviors and other factors with the potential to moderate such behavior during travel. However, it remains to be discussed whether the influence of demographic aspects, especially cultural and gender differences, on tourism behaviors will be more prominent during COVID-19. The current empirical research aims to integrate demographic variables, including gender and culture, with tourists' behavior in terms of their choice of companions, travel destinations, and mode of transportation. According to the research findings, people in other countries have greater desire to travel than Chinese tourists who, in any case, prefer to travel with friends. Tourists from other countries are more willing to travel by plane and by car. Males show a more positive attitude than females to these means of transportation. Moreover, the interactive effect of gender and nationality reveals that female travelers from mainland China put the train or bus top on their agenda. These theoretical findings have the potential to provide actionable insights into how policymakers and service providers can make adjustments to bring back tourism stifled by COVID-19. [ABSTRACT FROM AUTHOR]

Photosynthesis is an important plant metabolic mechanism that improves carbon absorption and crop yield. Photosynthetic efficiency is greatly hampered by cold stress (CS). Melatonin (ME) is a new plant growth regulator that regulates a wide range of abiotic stress responses. However, the molecular mechanism of ME-mediated photosynthetic regulation in cold-stressed plants is not well understood. Our findings suggest that under low-temperature stress (15/5 °C for 7 days), spraying the plant with ME (200 µM) enhanced gas exchange characteristics and the photosynthetic pigment content of pepper seedlings, as well as upregulated their biosynthetic gene expression. Melatonin increased the activity of photosynthetic enzymes (Rubisco and fructose-1, 6-bisphosphatase) while also enhancing starch, sucrose, soluble sugar, and glucose content under CS conditions. Low-temperature stress significantly decreased the photochemical activity of photosystem II (PSII) and photosystem I (PSI), specifically their maximum quantum efficiency PSII (Fv/Fm) and PSI (Pm). In contrast, ME treatment improved the photochemical activity of PSII and PSI. Furthermore, CS dramatically reduced the actual PSII efficiency (ΦPSII), electron transport rate (ETR) and photochemical quenching coefficient (qP), while enhancing nonphotochemical quenching (NPQ); however, ME treatment substantially mitigated the effects of CS. Our results clearly show the probable function of ME treatment in mitigating the effects of CS by maintaining photosynthetic performance, which might be beneficial when screening genotypes for CS tolerance. [ABSTRACT FROM AUTHOR]

Fruit color is one of the most critical characteristics of pepper. In this study, pepper (Capsicum baccatum L.) fruits with four trans-coloring periods were used as experimental materials to explore the color conversion mechanism of pepper fruit. By transcriptome and metabolome analysis, we identified a total of 307 flavonoid metabolites, 68 carotenoid metabolites, 29 DEGs associated with flavonoid biosynthesis, and 30 DEGs related to carotenoid biosynthesis. Through WGCNA (weighted gene co-expression network analysis) analysis, positively correlated modules with flavonoids and carotenoids were identified, and hub genes associated with flavonoid and carotenoid synthesis and transport were anticipated. We identified Pinobanksin, Naringenin Chalcone, and Naringenin as key metabolites in the flavonoid biosynthetic pathway catalyzed by the key genes chalcone synthase (CHS CQW23_29123, CQW23_29380, CQW23_12748), cinnamic acid 4-hydroxylase (C4H CQW23_16085, CQW23_16084), cytochrome P450 (CYP450 CQW23_19845, CQW23_24900). In addition, phytoene synthase (PSY CQW23_09483), phytoene dehydrogenase (PDS CQW23_11317), zeta-carotene desaturase (ZDS CQW23_19986), lycopene beta cyclase (LYC CQW23_09027), zeaxanthin epoxidase (ZEP CQW23_05387), 9-cis-epoxycarotenoid dioxygenase (NCED CQW23_17736), capsanthin/capsorubin synthase (CCS CQW23_30321) are key genes in the carotenoid biosynthetic pathway, catalyzing the synthesis of key metabolites such as Phytoene, Lycopene, β-carotene and ε-carotene. We also found that transcription factor families such as p450 and NBARC could play important roles in the biosynthesis of flavonoids and carotenoids in pepper fruits. These results provide new insights into the interaction mechanisms of genes and metabolites involved in the biosynthesis of flavonoids and carotenoids in pepper fruit leading to color changes in pepper fruit. [ABSTRACT FROM AUTHOR]

Light is the key factor affecting the synthesis of anthocyanins in pepper. In this study, pepper fruit under different light days was used as experimental material to explore the synthesis of anthocyanins in purple pepper. A total of 38 flavonoid metabolites were identified in the purple pepper germplasm HNUCA21 by liquid chromatography–tandem mass spectrometry (LC-MS/MS), of which 30 belong to anthocyanins. The detected anthocyanin with the highest content was Delphinidin-3-O-glucoside (17.13 µg/g), which reached the maximum after 168 h of light treatment. Through weighted gene co-expression network analysis (WGCNA), the brown module was identified to be related to the early synthesis of anthocyanins. This module contains many structural genes related to flavonoid synthesis, including chalcone synthase (CHS 107871256, 107864266), chalcone isomerase (CHI 107871144, 107852750), dihydroflavonol 4-reductase (DFR 107860031), flavonoid 3′ 5′-hydroxylase (F3'5'H 107848667), flavonoid 3′-monooxygenase (F3M 107862334), leucoanthocyanidin dioxygenase (LDOX 107866341), and trans-cinnamate 4-monooxygenase (TCM 107875406, 107875407). The module also contained some genes related to anthocyanin transport function, such as glutathione S-transferase (GST 107861273), anthocyanidin 3-O-glucosyltransferase (UDPGT 107861697, 107843659), and MATE (107863234, 107844661), as well as some transcription factors, such as EGL1 (107865400), basic helix-loop-helix 104 (bHLH104 107864591), and WRKY44 (107843538, 107843524). The co-expression regulatory network indicated the involvement of CHS, DFR, CHI, and EGL1, as well as two MATE and two WRKY44 genes in anthocyanin synthesis. The identified genes involved in early, middle, and late light response provided a reference for the further analysis of the regulatory mechanism of anthocyanin biosynthesis in pepper. [ABSTRACT FROM AUTHOR]

Heavy metal contamination is one of the current serious environmental and agricultural soil issues, and it is mainly due to anthropogenic activities. Vanadium (V) is found in low concentrations in a wide range of plants and is widely distributed in soils. The current study aimed to determine how pepper seedlings responded to various V concentrations, as well as the detrimental effects of V on growth, root morphological traits, photosynthetic performance, reactive oxygen species (ROS), osmolytes production, antioxidant enzyme activities, and V uptake. Pepper seedlings (5 weeks old) were grown in hydroponic culture with six V levels (0, 10, 20, 30, 40, and 50 mg L−1 NH4VO3). After two weeks of V treatment, low level of V (10, 20 mg L−1) enhanced the growth status, conversely higher V (30, 40, and 50 mg L−1) level reduced the growth. The leaf gas exchange elements, pigments molecules, and root growth characteristics are also affected by higher V concentrations. Moreover, V uptake was higher in roots than in the shoot of pepper seedlings. Similarly, osmolytes content, ROS production, and antioxidant enzymes activities were significantly improved under V stress. Concluding, lower V (10, 20 mg L−1) concentration positively affected pepper growth, and higher V (30, 40, and 50 mg L−1) concentration had a detrimental effect on pepper physiological and biochemical mechanisms. [ABSTRACT FROM AUTHOR]

Vegetation phenology is an important indicator of global climate change, and the response of grassland phenology to climate change is particularly sensitive in ecologically fragile areas. To enhance the ecological security of the Tibetan Plateau, it is crucial to determine the relationship between fluctuations in the start of the growing season (SOS) and the response to environmental factors. We investigated the trends of the intra-annual (ten-day) and interannual spatiotemporal dynamics of the SOS on the Northeast Qinghai-Tibet Plateau (NQTP) from 2000–2020 with MOD09GA data. We identified the response relationships with environmental factors (climate, terrain) using the maximum value composite method and the Savitzky–Golay filtering and dynamic threshold method. The SOS was concentrated from the 110th to 150th days; the average annual SOS was on the 128th day, with a spatial pattern of "early in the east and late in the west". The overall trend of the SOS was advanced (45.48%); the regions with the advanced trend were mainly distributed in the eastern part of the NQTP. The regions with a delayed SOS were mainly concentrated in the higher-altitude regions in the southwest (38.31%). The temperature, precipitation and SOS exhibited a reverse fluctuation trend around the midpoint of 2010. Precipitation affected the SOS earlier than temperature. When temperature became a limitation of the SOS, precipitation had a more significant regulatory effect on the SOS. The SOS and aspect, slope and altitude were distributed in axisymmetric, pyramidal and inverted pyramidal shapes, respectively. The SOS on shaded slopes was earlier and more intensive than that on sunny slopes. With increasing slope, the area of the SOS decreased, and it occurred later. The SOS area was largest at 4500–5000 m and decreased at lower and higher altitude intervals. The SOS occurred later as altitude increased. [ABSTRACT FROM AUTHOR]

Radish is a crucial vegetable crop of the Brassicaceae family with many varieties and large cultivated area in China. Radish is a cool season crop, and there are only a few heat tolerant radish varieties in practical production with little information concerning the related genes in response to heat stress. In this work, some physiological parameter changes of young leaves under short-term heat stress were detected. Furthermore, we acquired 1802 differentially expressed mRNAs (including encoding some heat shock proteins, heat shock factor and heat shock-related transcription factors), 169 differentially expressed lncRNAs and three differentially expressed circRNAs (novel_circ_0000265, novel_circ_0000325 and novel_circ_0000315) through strand-specific RNA sequencing technology. We also found 10 differentially expressed miRNAs (ath-miR159b-3p, athmiR159c, ath-miR398a-3p, athmiR398b-3p, ath-miR165a-5p, ath-miR169g-3p, novel_86, novel_107, novel_21 and ath-miR171b-3p) by small RNA sequencing technology. Through function prediction and enrichment analysis, our results suggested that the significantly possible pathways/complexes related to heat stress in radish leaves were circadian rhythm-plant, photosynthesis—antenna proteins, photosynthesis, carbon fixation in photosynthetic organisms, arginine and proline metabolism, oxidative phosphorylation, peroxisome and plant hormone signal transduction. Besides, we identified one lncRNA–miRNA–mRNAs combination responsive to heat stress. These results will be helpful for further illustration of molecular regulation networks of how radish responds to heat stress. [ABSTRACT FROM AUTHOR]