Closely related desert shrubs may allocate physiological and metabolic responses differently among organs. We integrated physiological measurements and untargeted LC–MS metabolomics to compare the leaves and roots of Reaumuria soongorica and Reaumuria kaschgarica collected from the same arid desert site. A 2 × 2 factorial analysis detected significant species × tissue interactions for superoxide dismutase and catalase activities, malondialdehyde and hydrogen peroxide contents, and the K/Na mass concentration ratio. The leaves of R. soongorica had higher catalase activity and malondialdehyde and hydrogen peroxide contents than the roots. In contrast, the roots of R. kaschgarica had higher superoxide dismutase and catalase activities, hydrogen peroxide content, and K/Na ratio than the leaves. A total of 2,324 and 2,308 metabolites were detected in positive- and negative-ion modes, respectively, and principal component analysis separated the four species–tissue groups. Pairwise comparisons revealed substantial organ- and species-associated differences in metabolite abundance. KEGG pathway enrichment highlighted differences involving amino acid, flavonoid, sugar, nucleotide-sugar, and carbon metabolism. Exploratory Spearman correlation networks revealed covariation between selected metabolites and physiological indicators. Together, these findings reveal contrasting organ-associated physiological and metabolic patterns in the two Reaumuria species and provide a basis for further investigation of their responses to arid environments.
Lentil (Lens culinaris Medik.) is an important source of plant-based protein and micronutrients. However, its productivity is increasingly threatened by concurrent drought and heat stress under changing climatic conditions. To elucidate the physiological and biochemical mechanisms underlying tolerance to combined water-deficit and heat (WD+HT) stress, two contrasting lentil genotypes, drought-tolerant PDL-1 and sensitive PSL-9, were evaluated under field and controlled-environment conditions. Under field conditions, terminal WD+HT stress significantly increased percent flower abortion by 52
Phytochromes are red/far-red light photoreceptors involved in plant growth, photomorphogenesis and developmental adaptation. Although phytochrome-mediated signaling pathways have been extensively investigated in model plant systems, limited information is available regarding the tissue-specific and developmental expression of phytochrome genes in cotton. In the present study, the expression dynamics of phytochrome genes (GhPHYA1, GhPHYA2, GhPHYB, GhPHYC and GhPHYE) were systematically analyzed across vegetative tissues, reproductive organs and fibre and boll developmental stages of upland cotton (Gossypium hirsutum L.) cv. MCU-5 using quantitative real-time PCR (qRT-PCR). Comparative expression profiling revealed pronounced spatial and temporal variation among phytochrome family members. GhPHYA1 and GhPHYA2 exhibited predominant transcript accumulation in juvenile vegetative tissues, floral organs, ovules at anthesis and early fibre developmental stages, whereas GhPHYB showed significantly higher expression in mature vegetative tissues and later stages associated with secondary cell wall deposition and fibre maturation. In contrast, GhPHYC and GhPHYE displayed relatively stable expression in all the tissues. Heatmap-based visualization further demonstrated spatio-temporal expression of phytochrome gene homologs across different tissues and developmental stages. Phylogenetic analysis confirmed that the cotton PHY family retains the canonical angiosperm subfamily organization, and promoter cis-element analysis identified light, hormone, stress and development-responsive motifs across all GhPHY genes. These findings establish a comprehensive, integrated expression atlas of cotton phytochrome genes, providing a foundational resource for future functional and regulatory studies of light-mediated development in cotton.
Global climate change, ever-increasing population and decreasing arable land pose a major challenge for food security and sustainable agriculture. To address the growing needs of the global population, food production worldwide must be increased by more than double by the year 2050. Nitrogen is one of the important elements which is required for plant growth and yield and therefore adequate nitrogen supply will be critical to achieving this ambitious goal. Improving nitrogen use efficiency (NUE) stands at the centre stage for sustainable and climate-resilient agriculture as excessive use of nitrogen fertilisers proves detrimental to soil health, environmental pollution, putting an extra burden on the pocket. In this regard, increasing nitrogen use efficiency of the crop plants is a possible solution to tackle this problem. In the past, many efforts were made to dissect the variation in NUE- related traits, exploring many genes or TFs responsible for increasing NUE and studying their molecular mechanism. Nitrate and ammonium transporters (NRTs and AMTs), as well as signaling components such as NLP transcription factors, primarily facilitate nitrogen uptake but do not significantly improve yield in nitrogen-limited conditions. After uptake, nitrate is converted to ammonium by nitrate reductase and nitrite reductase. The resulting ammonia is then assimilated using the GS/GOGAT or Fd/GOGAT cycles. Since, NUE depends not only on nitrogen uptake but also on its assimilation, utilization and remobilization, there is need to identify better players for enhancing NUE under nitrogen limiting conditions. Recently, genetic screening of rice accessions has identified a gene which acts downstream of nitrogen uptake and involved in redistribution of nitrogen under nitrogen limiting condition. ARE1 (ABNORMAL CYTOKININ RESPONSE 1 REPRESSOR 1), a highly conserved gene, encodes a chloroplast-localized protein that negatively regulates nitrogen utilization and Fd/GOGAT cycle reducing nitrogen assimilation, making it a promising candidate for crop improvement through genome editing. Loss of function mutations of ARE1 enhance the efficiency of nitrogen utilization by maintaining chloroplast functions, delaying leaf senescence, extending photosynthesis, and increasing grain yield under a low nitrogen supply without compromising normal plant development. Thus, ARE1 should not only be regarded as an additional NUE-related gene but also as an important molecular target for the development of nitrogen-efficient, climate-resilient, and high-yielding crops by using advanced genome-editing and precision-breeding. Here, we provide a comprehensive overview of the emerging role of ARE1 in the regulation of nitrogen use efficiency by integrating existing knowledge on the molecular function, evolutionary conservation, natural variation, genome editing, and the relationships of ARE1 with nitrogen sensing, assimilation, carbon metabolism, and crop improvement.
