Publications

Drought stress and phosphorus (P) deficit decrease soybean P and nitrogen (N) accumulation, which limits soybean productivity. Therefore, soybean traits related to N and P uptake and/or their efficient utilization are important for soybean adaptation to P- and water-deficit conditions. We hypothesize that increasing soybean nodulation to enhance N and P uptake, and/or improving N and P use efficiency (PUE and NUE) are important for the adaptation of soybean to drought and low P conditions. To test this hypothesis, we selected four genotypes with different nodule dry weight (DW) and yield performance for a pot experiment under two water treatments [well-watered (WW) and cycle water stress (WS)] and three P levels [0 (P0, low), 60 (P60, mid), and 120 (P120, high) mg P kg−1 dry soil on top 40 cm]. Our study showed that P deficit and water stress significantly decreased soybean P and N accumulation, which limited seed yield under both WS and WW conditions. P addition increased soybean nodule dry weight (DW), thus increasing N and P uptake. Increasing nodule DW required high water use, and while there was no relationship found between nodule DW and yield under WS, a positive relationship under WW was shown. Partitioning more dry matter to seed could improve NUE and PUE. P addition did not change soybean NUE, which is important to yield determination under WS and P0 but has no effect on yield under WW. We conclude that increasing nodule formation improved soybean N and P uptake, which diminished the yield loss under WS and improved yield performance under WW. While high NUE reflects efficient utilization of N, which can improve yield under drought stress and low P availability, and does not impair the yield under WW. We propose that NUE and nodules are important traits for breeders to improve the tolerance to water- and P-deficit conditions.

This study revealed significant enrichment of DEGs in GO and KEGG terms linked to glutathione, flavonoids, and phenylpropane pathways, indicating the potential role of glutathione and flavonoids in early BW resistance in tobacco roots. These findings offer fundamental insight for further exploration of the genetic architecture and molecular mechanisms of BW resistance in tobacco and solanaceous plants at the molecular level.

Inefficient phosphorus (P) fertilizer application often accumulates soil P, wasting valuable phosphate resources and contributing to environmental pollution. Given the suboptimal P fertilizer use efficiency (PUE), understanding soil P dynamics and selecting appropriate fertilizers is crucial. Fluvo-aquic soil and yellow-cinnamon soils were used in a rice pot trial to compare five P fertilizer types: single superphosphate (SSP), diammonium phosphate (DAP), calcium magnesium phosphate (CMP), triple superphosphate (TSP), and ammonium polyphosphate (APP), alongside a no P, control (CK). In fluvo-aquic soil, TSP and APP significantly increased rhizosphere P availability at anthesis, while SSP increased yield and shoot P accumulation at maturity. In yellow-cinnamon soil, DAP had the highest rhizosphere P availability at anthesis, while APP significantly increased shoot P accumulation at anthesis and shoot P accumulation and grain yield at maturity. Moreover, PUE was highest with SSP and CMP in fluvo-aquic soil and APP and TSP in yellow-cinnamon soil. Throughout the experiment, increased soil alkaline phosphatase activity promoted NaOH-Po conversion to NaHCO3-Pi, increasing rice shoot P uptake, yield, and PUE in both soils. Based on the above findings, it is recommended to apply SSP and TSP to fluvo-aquic soil and APP and TSP to yellow-cinnamon soil to achieve higher yield and PUE, which can be further confirmed by subsequent field-scale studies.

Increasing temperature affects all food crops, thereby reducing their yield potential. Chickpea is a cool-season food legume vital for its nutritive value, but it is sensitive to high temperatures (> 32/20 °C maximum/minimum) during its reproductive and seed-filling stages. This study evaluated the effects of heat stress on yield and qualitative traits of chickpea seeds in a controlled environment. Chickpea genotypes differing in heat sensitivity [two heat-tolerant (HT) and two heat-sensitive (HS)] were raised in pots, initially in an outdoor environment (average 23.5/9.9 °C maximum/minimum), until the beginning of pod set (107-110 days after sowing). At this stage, the plants were moved to a controlled environment in the growth chamber to impose heat stress (32/20 °C) at the seed-filling stage, while maintaining a set of control plants at 25/15 °C. The leaves of heat-stressed plants of the HT and HS genotypes showed considerable membrane damage, altered stomatal conductance, and reduced leaf water content, chlorophyll content, chlorophyll fluorescence, and photosynthetic ability (RuBisCo, sucrose phosphate synthase, and sucrose activities) relative to their corresponding controls. Seed filling duration and seed rate drastically decreased in heat-stressed plants of the HT and HS genotypes, severely reducing seed weight plant^-1 and single seed weight, especially in the HS genotypes. Yield-related traits, such as pod number, seed number, and harvest index, noticeably decreased in heat-stressed plants and more so in the HS genotypes. Seed components, such as starch, proteins, fats, minerals (Ca, P, and Fe), and storage proteins (albumin, globulins, glutelin, and prolamins), drastically declined, resulting in poor-quality seeds, particularly in the HS genotypes. These findings revealed that heat stress significantly reduced leaf sucrose production, affecting the accumulation of various seed constituents, and leading to poor nutritional quality. The HT genotypes were less affected than the HS genotypes because of the greater stability of their leaf water status and photosynthetic ability, contributing to better yield and seed quality traits in a heat-stressed environment.

Biofortification of zinc (Zn), iron (Fe) and selenium (Se) in crops could be affected by environmental factors such as soil salinity and phosphorus supply levels, as well as by the genotypic effect. Two pot experiments were conducted with one examined the effects of P supply and salinity on plant growth and Zn, Fe and Se uptake in wheat, and the other examined genotypic differences in Zn, Fe and Se accumulation among 20 wheat genotypes. The results of the first pot study showed significant interactive effects between P supply and salinity on Zn, Fe and Se accumulation. Increasing salinity at the same P supply level increased shoot Zn concentrations, but significantly decreased total shoot Zn amount owing to decreased aboveground biomass. An increased accumulation of total shoot Fe and Se in P-added treatments, relative to the no-P treatments, was mainly due to increased aboveground biomass. The results of the second pot study showed substantial genotypic variations in Zn, Fe and Se accumulation; principal component analysis (PCA) suggested that agronomic traits and nutrient accumulation were controlled by independent genetic mechanisms. These results indicated that the amount of P supply is a key factor regulating biomass and accumulation of Zn, Fe and Se in certain saline soils; the sizable genotypic difference in Zn, Fe and Se accumulation observed in salinised conditions has provided potential scope for genetic improvement by breeding strategies.

This study explored the spatiotemporal characteristics of drought and ecosystem services (using soil conservation services as an example) in the YanHe Watershed, which is a typical water basin in the Loess Plateau of China, experiencing soil erosion. Herein, soil conservation was simulated using the Soil and Water Assessment Tool (SWAT), and the relationship between drought, soil conservation services, and meteorological, vegetation, and other factors since the implementation of the ‘Grain for Green’ Project (GFGP) in 1999, were analyzed using the gray relational analysis (GRA) method. The results showed that: (1) The vegetation cover of the Watershed has increased significantly, and evapotranspiration (ET) increased by 14.35 mm·a−1, thereby increasing water consumption by 8.997 × 108 m3·a−1 (compared to 2000). (2) Drought affected 63.86% of the watershed area, gradually worsening from south to north; it decreased in certain middle areas but increased in the humid areas on the southern edge. (3) The watershed soil conservation services, measured by the soil conservation modulus (SCM), increased steadily from 116.87 t·ha−1·a−1 in 2000 to 412.58 t·ha−1·a−1 in 2015, at a multi-year average of 235.69 t·ha−1·a−1, and indicated great spatial variations, with a large variation in the downstream and small variations in the upstream and midstream areas. (4) Integrating normalized difference vegetation index (NDVI) data into SWAT model improved the model simulation accuracy; during the calibration period, the coefficient of determination (R2) increased from 0.63 to 0.76 and Nash–Sutcliffe efficiency (NSE) from 0.46 to 0.51; and during the validation period, the R2 increased from 0.82 to 0.93 and the NSE from 0.57 to 0.61. (5) The GRA can be applied to gray control systems, such as the ecosystem; herein, vegetation cover and drought primarily affected ET and soil conservation services. The analysis results showed that vegetation restoration enhanced the soil conservation services, but increased ET and aggravated drought to a certain extent. This study analyzed the spatiotemporal variations in vegetation coverage and the response of ET to vegetation restoration in the YanHe Watershed, to verify the significant role of vegetation restoration in restraining soil erosion and evaluate the extent of water resource consumption due to ET in the semi-arid and semi-humid Loess-area basin during the GFGP period. Thus, this approach may effectively provide a scientific basis for evaluating the ecological effects of the GFGP and formulating policies to identify the impact of human ecological restoration on ecosystem services.

Plants are regularly exposed to biotic and abiotic stresses that adversely affect agricultural production. Omics has gained momentum in the last two decades, fueled by statistical methodologies, computational capabilities, mass spectrometry, nucleic-acid sequencing, and peptide-sequencing platforms. Functional genomics-especially metabolomics, transcriptomics, and proteomics-have contributed substantially to plant molecular responses to stress. Recent progress in reverse and forward genetics approaches have mediated high-throughput techniques for identifying stress-related genes. Furthermore, web-based genetic databases have mediated bioinformatics techniques for detecting families of stress-tolerant genes. Gene ontology (GO) databases provide information on the gene product's functional features and help with the computational estimation of gene function. Functional omics data from multiple platforms are useful for positional cloning. Stress-tolerant plants have been engineered using stress response genes, regulatory networks, and pathways. The genome-editing tool, CRISPR-Cas9, reveals the functional features of several parts of the plant genome. Current developments in CRISPR, such as <i>de novo</i> meristem induction genome-engineering in dicots and temperature-tolerant LbCas12a/CRISPR, enable greater DNA insertion precision. This review discusses functional omics for molecular insight and CRISPR-Cas9-based validation of gene function in crop plants. Omics and CRISPR-Cas9 are expected to garner knowledge on molecular systems and gene function and stress-tolerant crop production.

Climate change gives rise to numerous environmental stresses, including soil salinity. Salinity/salt stress is the second biggest abiotic factor affecting agricultural productivity worldwide by damaging numerous physiological, biochemical, and molecular processes. In particular, salinity affects plant growth, development, and productivity. Salinity responses include modulation of ion homeostasis, antioxidant defense system induction, and biosynthesis of numerous phytohormones and osmoprotectants to protect plants from osmotic stress by decreasing ion toxicity and augmented reactive oxygen species scavenging. As most crop plants are sensitive to salinity, improving salt tolerance is crucial in sustaining global agricultural productivity. In response to salinity, plants trigger stress-related genes, proteins, and the accumulation of metabolites to cope with the adverse consequence of salinity. Therefore, this review presents an overview of salinity stress in crop plants. We highlight advances in modern biotechnological tools, such as omics (genomics, transcriptomics, proteomics, and metabolomics) approaches and different genome editing tools (ZFN, TALEN, and CRISPR/Cas system) for improving salinity tolerance in plants and accomplish the goal of "zero hunger," a worldwide sustainable development goal proposed by the FAO.

Chickpea (Cicer arietinum L.), a vital cool-season pulse crop, experiences significant yield losses when exposed to heat stress during its reproductive stages, a vulnerability exacerbated by weather extremes. Chickpea plants synthesize numerous metabolites when subjected to heat stress; however, the underlying metabolomic mechanisms of heat tolerance remain poorly understood. In this study, we employed widely targeted metabolomics to identify key metabolites and potential biomarkers in the flower buds of two contrasting chickpea genotypes: the heat-tolerant PI518255 and the heat-sensitive PI598080. The tolerant genotype showed improved chlorophyll index, photochemical efficiency, antioxidant activity, along with low electrolyte leakage and malondialdehyde content. In contrast, the sensitive genotype exhibited low chlorophyll index, photochemical efficiency and low antioxidant activity, and high electrolyte leakage and malondialdehyde content, under heat stress conditions (35/20 °C day/night). Volcano plot analysis identified 86 up-regulated and 230 down-regulated metabolites in response to heat stress. Heatmap analysis revealed that elevated levels of specific flavonoids, phenolic acids, lignans, coumarins, alkaloids, quinones, and terpenoids characterized the heat-tolerant genotype, suggesting their potential as biomarkers for screening heat stress tolerance. KEGG enrichment and pathway analysis highlighted isoflavonoid biosynthesis, flavonoid metabolism, lysine degradation, and butanoate metabolism as key pathways affected by heat stress. Future targeted metabolomics studies may provide deeper insights into the biochemical mechanisms underlying chickpea acclimation to heat stress.

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