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<jats:p>The paper introduces two novel algorithms for predicting and propagating drought stress in plants using image sequences captured by cameras in two modalities, i.e., visible light and hyperspectral. The first algorithm, VisStressPredict, computes a time series of holistic phenotypes, e.g., height, biomass, and size, by analyzing image sequences captured by a visible light camera at discrete time intervals and then adapts dynamic time warping (DTW), a technique for measuring similarity between temporal sequences for dynamic phenotypic analysis, to predict the onset of drought stress. The second algorithm, HyperStressPropagateNet, leverages a deep neural network for temporal stress propagation using hyperspectral imagery. It uses a convolutional neural network to classify the reflectance spectra at individual pixels as either stressed or unstressed to determine the temporal propagation of stress in the plant. A very high correlation between the soil water content, and the percentage of the plant under stress as computed by HyperStressPropagateNet on a given day demonstrates its efficacy. Although VisStressPredict and HyperStressPropagateNet fundamentally differ in their goals and hence in the input image sequences and underlying approaches, the onset of stress as predicted by stress factor curves computed by VisStressPredict correlates extremely well with the day of appearance of stress pixels in the plants as computed by HyperStressPropagateNet. The two algorithms are evaluated on a dataset of image sequences of cotton plants captured in a high throughput plant phenotyping platform. The algorithms may be generalized to any plant species to study the effect of abiotic stresses on sustainable agriculture practices.</jats:p>

<jats:sec><jats:title>Background</jats:title><jats:p>The CorA / MGT / MRS2 family proteins are an important group of magnesium transporter proteins that maintain magnesium ion homeostasis in plant cells. However, little is known about the MGT functions in wheat.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>The known MGT sequences were used as queries to BlastP against wheat genome IWGSC RefSeq v2.1 assembly (E-value &amp;lt;10–5). Chromosome localization information for each <jats:italic>TaMGT</jats:italic> gene was obtained from the GFF3 file of the wheat genome data (IWGSCv2.1).The sequence of 1500 bp upstream of the <jats:italic>TaMGT</jats:italic> genes was extracted from the wheat genome data. The cis-elements were analyzed using PlantCARE online tool.</jats:p></jats:sec><jats:sec><jats:title>Result</jats:title><jats:p>A total of 24 <jats:italic>MGT</jats:italic> genes were identified on 18 chromosomes of wheat. After functional domain analysis, only <jats:italic>TaMGT1A</jats:italic>, <jats:italic>TaMGT1B</jats:italic>, and <jats:italic>TaMGT1D</jats:italic> had GMN mutations to AMN, while all the other genes had conserved GMN tripeptide motifs. Expression profiling showed that the <jats:italic>TaMGT</jats:italic> genes were differentially expressed under different stresses and at different growth and development stages. The expression levels of <jats:italic>TaMGT4B</jats:italic> and <jats:italic>TaMGT4A</jats:italic> were significantly up-regulated in cold damage. In addition, qRT-PCR results also confirmed that these <jats:italic>TaMGT</jats:italic> genes are involved in the wheat abiotic stress responses.</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>In conclusion, The results of our research provide a theoretical basis for further research on the function of <jats:italic>TaMGT</jats:italic> gene family in wheat.</jats:p></jats:sec>

<jats:p>Drylands dominate the trend and variability of the land carbon (C) sink. A better understanding of the implications of climate-induced changes in the drylands for C sink-source dynamics is urgently needed. The effect of climate on ecosystem C fluxes (gross primary productivity (GPP), ecosystem respiration (ER), and net ecosystem productivity (NEP)) in drylands has been extensively explored, but the roles of other concurrently changing factors, such as vegetation conditions and nutrient availability, remain unclear. We used eddy-covariance C-flux measurements from 45 ecosystems with concurrent information on climate (mean annual temperature (MAT) and mean annual precipitation (MAP)), soil (soil moisture (SM) and soil total nitrogen content (soil N)), and vegetation (leaf area index (LAI) and leaf nitrogen content (LNC)) factors to assess their roles in C fluxes. The results showed that the drylands in China were weak C sinks. GPP and ER were positively correlated with MAP, while they were negatively correlated with MAT. NEP first decreased and then increased with increasing MAT and MAP, and 6.6 °C and 207 mm were the boundaries for the NEP response to MAT and MAP, respectively. SM, soil N, LAI, and MAP were the main factors affecting GPP and ER. However, SM and LNC had the most important influence on NEP. Compared with climate and vegetation factors, soil factors (SM and soil N) had a greater impact on C fluxes in the drylands. Climate factors mainly affected C fluxes by regulating vegetation and soil factors. To accurately estimate the global C balance and predict the response of ecosystems to environmental change, it is necessary to fully consider the discrepant effects of climate, vegetation, and soil factors on C fluxes, as well as the cascade relationships between different factors.</jats:p>

<jats:p>Plant growth-promoting bacteria (PGPB) represent an eco-friendly alternative to reduce the use of chemical products while increasing the productivity of economically important crops. The emission of small gaseous signaling molecules from PGPB named volatile organic compounds (VOCs) has emerged as a promising biotechnological tool to promote biomass accumulation in model plants (especially <jats:italic>Arabidopsis thaliana</jats:italic>) and a few crops, such as tomato, lettuce, and cucumber. Rice (<jats:italic>Oryza sativa</jats:italic>) is the most essential food crop for more than half of the world’s population. However, the use of VOCs to improve this crop performance has not yet been investigated. Here, we evaluated the composition and effects of bacterial VOCs on the growth and metabolism of rice. First, we selected bacterial isolates (IAT P4F9 and E.1b) that increased rice dry shoot biomass by up to 83% in co-cultivation assays performed with different durations of time (7 and 12 days). Metabolic profiles of the plants co-cultivated with these isolates and controls (without bacteria and non-promoter bacteria—1003-S-C1) were investigated <jats:italic>via</jats:italic><jats:sup>1</jats:sup>H nuclear magnetic resonance. The analysis identified metabolites (e.g., amino acids, sugars, and others) with differential abundance between treatments that might play a role in metabolic pathways, such as protein synthesis, signaling, photosynthesis, energy metabolism, and nitrogen assimilation, involved in rice growth promotion. Interestingly, VOCs from IAT P4F9 displayed a more consistent promotion activity and were also able to increase rice dry shoot biomass <jats:italic>in vivo</jats:italic>. Molecular identification by sequencing the 16S rRNA gene of the isolates IAT P4F9 and E.1b showed a higher identity with <jats:italic>Serratia</jats:italic> and <jats:italic>Achromobacter</jats:italic> species, respectively. Lastly, volatilomes of these and two other non-promoter bacteria (1003-S-C1 and <jats:italic>Escherichia coli</jats:italic> DH5α) were evaluated through headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry. Compounds belonging to different chemical classes, such as benzenoids, ketones, alcohols, sulfide, alkanes, and pyrazines, were identified. One of these VOCs, nonan-2-one, was validated <jats:italic>in vitro</jats:italic> as a bioactive compound capable of promoting rice growth. Although further analyses are necessary to properly elucidate the molecular mechanisms, our results suggest that these two bacterial isolates are potential candidates as sources for bioproducts, contributing to a more sustainable agriculture.</jats:p>

<jats:p>Leaf senescence in tobacco is closely related to leaf maturation and secondary metabolites. Bcl-2-associated athanogene (BAG) family members are highly conserved proteins and play key roles in senescence, growth and development, and resistance to biotic and abiotic stresses. Herein, the BAG family of tobacco was identified and characterized. In total, 19 tobacco BAG protein candidate genes were identified and divided into two classes, class I comprising <jats:italic>NtBAG1a–e</jats:italic>, <jats:italic>NtBAG3a–b</jats:italic>, and <jats:italic>NtBAG4a–c</jats:italic> and class II including <jats:italic>NtBAG5a–e</jats:italic>, <jats:italic>NtBAG6a–b</jats:italic>, and <jats:italic>NtBAG7</jats:italic>. Genes in the same subfamily or branch of the phylogenetic tree exhibited similarities in gene structure and the <jats:italic>cis</jats:italic>-element on promoters. RNA-seq and real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) revealed that the expression of <jats:italic>NtBAG5c–f</jats:italic> and <jats:italic>NtBAG6a–b</jats:italic> was upregulated in senescent leaves, implying that they play a role in regulating leaf senescence. <jats:italic>NtBAG5c</jats:italic> was localized in the nucleus and cell wall as a homology of leaf senescence related gene <jats:italic>AtBAG5</jats:italic>. Further, the interaction of NtBAG5c with heat-shock protein 70 (HSP70) and sHSP20 was demonstrated using yeast two-hybrid experiment. Virus-induced gene silencing indicated that <jats:italic>NtBAG5c</jats:italic> reduced the lignin content and increased superoxide dismutase (SOD) activity and hydrogen peroxide (H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>) accumulation. In <jats:italic>NtBAG5c</jats:italic>-silenced plants, the expression of multiple senescence-related genes cysteine proteinase (<jats:italic>NtCP1)</jats:italic>, <jats:italic>SENESCENCE 4</jats:italic> (<jats:italic>SEN4</jats:italic>) and <jats:italic>SENESCENCE-ASSOCIATED GENE 12</jats:italic> (<jats:italic>SAG12</jats:italic>) was downregulated. In conclusion, tobacco BAG protein candidate genes were identified and characterized for the first time.</jats:p>

<jats:p>Peanut is an important oil and food legume crop grown in more than one hundred countries, but the yield and quality are often impaired by different pathogens and diseases, especially aflatoxins jeopardizing human health and causing global concerns. For better management of aflatoxin contamination, we report the cloning and characterization of a novel <jats:italic>A. flavus</jats:italic> inducible promoter of the O-methyltransferase gene (<jats:italic>AhOMT1</jats:italic>) from peanut. The <jats:italic>AhOMT1</jats:italic> gene was identified as the highest inducible gene by <jats:italic>A. flavus</jats:italic> infection through genome-wide microarray analysis and verified by qRT-PCR analysis. <jats:italic>AhOMT1</jats:italic> gene was studied in detail, and its promoter, fussed with the <jats:italic>GUS</jats:italic> gene, was introduced into Arabidopsis to generate homozygous transgenic lines. Expression of <jats:italic><jats:italic>GUS</jats:italic></jats:italic> gene was studied in transgenic plants under the infection of <jats:italic>A. flavus</jats:italic>. The analysis of <jats:italic>AhOMT1</jats:italic> gene characterized by in silico assay, RNAseq, and qRT-PCR revealed minute expression in different organs and tissues with trace or no response to low temperature, drought, hormones, Ca2+, and bacterial stresses, but highly induced by <jats:italic>A. flavus</jats:italic> infection. It contains four exons encoding 297 aa predicted to transfer the methyl group of S-adenosyl-L-methionine (SAM). The promoter contains different cis-elements responsible for its expression characteristics. Functional characterization of <jats:italic>AhOMT1</jats:italic>P in transgenic Arabidopsis plants demonstrated highly inducible behavior only under <jats:italic>A. flavus</jats:italic> infection. The transgenic plants did not show <jats:italic><jats:italic>GUS</jats:italic></jats:italic> expression in any tissue(s) without inoculation of <jats:italic>A. flavus</jats:italic> spores. However, <jats:italic>GUS</jats:italic> activity increased significantly after inoculation of <jats:italic>A. flavus</jats:italic> and maintained a high level of expression after 48 hours of infection. These results provided a novel way for future management of peanut aflatoxins contamination through driving resistance genes in <jats:italic>A. flavus</jats:italic> inducible manner.</jats:p>

<jats:p><jats:italic>Sitobion miscanthi</jats:italic>, <jats:italic>Rhopalosiphum padi</jats:italic>, and <jats:italic>Schizaphis graminum</jats:italic> are the three main pests in Chinese wheat-producing regions. In 2020, they are classified into the Chinese Class I list of agricultural diseases and pests, due to their severe harm to wheat plantings. <jats:italic>S. miscanthi</jats:italic>, <jats:italic>R. padi</jats:italic>, and <jats:italic>S. graminum</jats:italic> are migrant pests, and understanding their migration patterns and simulating their migration trajectories would improve forecasting and controlling them. Furthermore, the bacterial community of the migrant wheat aphid is also less known. In this study, we employed a suction trap to uncover the migration patterns of the three wheat aphid species in Yuanyang county, Henan province, during 2018 to 2020. And then the migration trajectories of <jats:italic>S. miscanthi</jats:italic> and <jats:italic>R. padi</jats:italic> were simulated using the NOAA HYSPLIT model. The interactions between wheat aphids and bacteria were further revealed by specific PCR and 16S rRNA amplicon sequencing. The results showed that the population dynamics of migrant wheat aphids was varied. Most of the trapped samples were identified to be <jats:italic>R. padi</jats:italic>, and <jats:italic>S. graminum</jats:italic> was the least collected sample. Typically, <jats:italic>R. padi</jats:italic> had two migration peaks in the 3 years, whereas <jats:italic>S. miscanthi</jats:italic> and <jats:italic>S. graminum</jats:italic> only exhibited one migration peak in 2018 and 2019. Moreover, the aphid migration trajectories varied over the years. Generally, the aphids originated from the south and migrated to the north. Herein, the infections of three main aphid facultative bacterial symbionts, <jats:italic>Serratia symbiotica</jats:italic>, <jats:italic>Hamiltonella defensa</jats:italic>, and <jats:italic>Regiella insercticola</jats:italic>, were detected in <jats:italic>S. miscanthi</jats:italic> and <jats:italic>R. padi</jats:italic> with specific PCR. <jats:italic>Rickettsiella</jats:italic>, <jats:italic>Arsenophonus</jats:italic>, <jats:italic>Rickettsia</jats:italic>, and <jats:italic>Wolbachia</jats:italic> were further identified with 16S rRNA amplicon sequencing. Biomarker searching indicated that <jats:italic>Arsenophonus</jats:italic> was significantly enriched in <jats:italic>R. padi</jats:italic>. Furthermore, diversity analyses showed that the bacterial community of <jats:italic>R. padi</jats:italic> had a higher richness and evenness than that of <jats:italic>S. miscanthi</jats:italic>. In conclusion, this study expands our knowledge about the migration patterns of aphids in the main wheat plant region of China and reveals the interactions between bacterial symbionts and migrant aphids.</jats:p>

<jats:sec><jats:title>Introduction</jats:title><jats:p>Grape rootstocks play critical role in the development of the grape industry over the globe for their higher adaptability to various environments, and the evaluation of their genetic diversity among grape genotypes is necessary to the conservation and utility of genotypes.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>To analyze the genetic diversity of grape rootstocks for a better understanding multiple resistance traits, whole-genome re-sequencing of 77 common grape rootstock germplasms was conducted in the present study.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>About 645 billion genome sequencing data were generated from the 77 grape rootstocks at an average depth of ~15.5×, based on which the phylogenic clusters were generated and the domestication of grapevine rootstocks was explored. The results indicated that the 77 rootstocks originated from five ancestral components. Through phylogenetic, principal components, and identity-by-descent (IBD) analyses, these 77 grape rootstocks were assembled into ten groups. It is noticed that the wild resources of <jats:italic>V. amurensis</jats:italic> and <jats:italic>V. davidii</jats:italic>, originating from China and being generally considered to have stronger resistance against biotic and abiotic stresses, were sub-divided from the other populations. Further analysis indicated that a high level of linkage disequilibrium was found among the 77 rootstock genotypes, and a total of 2,805,889 single nucleotide polymorphisms (SNPs) were excavated, GWAS analysis among the grape rootstocks located 631, 13, 9, 2, 810, and 44 SNP loci that were responsible to resistances to phylloxera, root-knot nematodes, salt, drought, cold and waterlogging traits.</jats:p></jats:sec><jats:sec><jats:title>Discussion</jats:title><jats:p>This study generated a significant amount of genomic data from grape rootstocks, thus providing a theoretical basis for further research on the resistance mechanism of grape rootstocks and the breeding of resistant varieties. These findings also reveal that China originated <jats:italic>V. amurensis</jats:italic> and <jats:italic>V. davidii</jats:italic> could broaden the genetic background of grapevine rootstocks and be important germplasm used in breeding high stress-resistant grapevine rootstocks.</jats:p></jats:sec>