Increased levels of greenhouse gases in the atmosphere and associated climatic variability is primarily responsible for inducing heat waves, flooding and drought stress. Among these, water scarcity is a major limitation to crop productivity. Water stress can severely reduce crop yield and both the severity and duration of the stress are critical. Water availability is a key driver for sustainable cotton production and its limitations can adversely affect physiological and biochemical processes of plants, leading towards lint yield reduction. Adaptation of crop husbandry techniques suitable for cotton crop requires a sound understanding of environmental factors, influencing cotton lint yield and fiber quality. Various defense mechanisms e.g. maintenance of membrane stability, carbon fixation rate, hormone regulation, generation of antioxidants and induction of stress proteins have been found play a vital role in plant survival under moisture stress. Plant molecular breeding plays a functional role to ascertain superior genes for important traits and can offer breeder ready markers for developing ideotypes. This review highlights drought-induced damage to cotton plants at structural, physiological and molecular levels. It also discusses the opportunities for increasing drought tolerance in cotton either through modern gene editing technology like clustered regularly interspaced short palindromic repeat (CRISPR/Cas9), zinc finger nuclease, molecular breeding as well as through crop management, such as use of appropriate fertilization, growth regulator application and soil amendments.

The current farming system is heavily reliant on chemical fertilizers, which negatively affect soil health, the environment, and crop productivity. Improving crop production on a sustainable basis is a challenging issue in the present agricultural system. To address this issue, we assumed that the combined use of organic manure and inorganic nitrogen (N) fertilizers can improve rice grain yield and soil properties without the expense of the environment. This study explores the combined effects of cattle manure (CM), poultry manure (PM), and chemical fertilizer (CF) on soil properties, rice growth, physiology, and grain yield and quality. Six treatments in the following combinations were included: T₁—no N fertilizer; T₂—100% CF; T₃—60% CM + 40% CF; T₄—30% CM + 70% CF; T₅—60% PM + 40% CF; and T₆—30% PM + 70% CF. Results showed that across the seasons, treatment T₆ increased the net photosynthesis rate, total biomass, grain yield, and amylose content by 23%, 90%, 95%, and 10%, respectively, compared with control. This increment in net photosynthetic rate and growth was the result of 24%, 14%, 19%, and 20% higher total root length, root surface area, root volume, and root diameter, respectively. Improvements in these attributes further enhanced the grain yield and nitrogen use efficiency of rice. No significant difference between T₄ and T₆ was observed. The correlation analysis also confirmed that root morphological traits were positively correlated with grain yield, N uptake, and biomass accumulation. Similarly, improvement in grain yield and NUE was also associated with improved soil properties, i.e., bulk density, soil porosity, soil organic carbon, and total N under combined organic and inorganic N fertilizers treatment. Conclusively, the integration of 30% N from PM or CM with 70% N from CF (urea) is a promising option not only for higher grain yield and quality of rice but also for improved soil health. This study provides a sustainable nutrient management strategy to improve crop yield with high nutrient use efficiency.

Cold stress strongly hinders plant growth and development. However, the molecular and physiological adaptive mechanisms of cold stress tolerance in plants are not well understood. Plants adopt several morpho-physiological changes to withstand cold stress. Plants have evolved various strategies to cope with cold stress. These strategies included changes in cellular membranes and chloroplast structure, regulating cold signals related to phytohormones and plant growth regulators (ABA, JA, GA, IAA, SA, BR, ET, CTK, and MET), reactive oxygen species (ROS), protein kinases, and inorganic ions. This review summarizes the mechanisms of how plants respond to cold stress, covering four main signal transduction pathways, including the abscisic acid (ABA) signal transduction pathway, Ca²⁺ signal transduction pathway, ROS signal transduction pathway, and mitogen-activated protein kinase (MAPK/MPK) cascade pathway. Some transcription factors, such as AP2/ERF, MYB, WRKY, NAC, and bZIP, not only act as calmodulin-binding proteins during cold perception but can also play important roles in the downstream chilling-signaling pathway. This review also highlights the analysis of those transcription factors such as bHLH, especially bHLH-type transcription factors ICE, and discusses their functions as phytohormone-responsive elements binding proteins in the promoter region under cold stress. In addition, a theoretical framework outlining plant responses to cold stress tolerance has been proposed. This theory aims to guide future research directions and inform agricultural production practices, ultimately enhancing crop resilience to cold stress.

The textile industry is one of the most chemically intensive industries, and its wastewater is comprised of harmful dyes, pigments, dissolved/suspended solids, and heavy metals. The treatment of textile wastewater has become a necessary task before discharge into the environment. The textile effluent can be treated by conventional methods, however, the limitations of these techniques are high cost, incomplete removal, and production of concentrated sludge. This review illustrates recent knowledge about the application of floating treatment wetlands (FTWs) for remediation of textile wastewater. The FTWs system is a potential alternative technology for textile wastewater treatment. FTWs efficiently removed the dyes, pigments, organic matter, nutrients, heavy metals, and other pollutants from the textile effluent. Plants and bacteria are essential components of FTWs, which contribute to the pollutant removal process through their physical effects and metabolic process. Plants species with extensive roots structure and large biomass are recommended for vegetation on floating mats. The pollutant removal efficiency can be enhanced by the right selection of plants, managing plant coverage, improving aeration, and inoculation by specific bacterial strains. The proper installation and maintenance practices can further enhance the efficiency, sustainability, and aesthetic value of the FTWs. Further research is suggested to develop guidelines for the selection of right plants and bacterial strains for the efficient remediation of textile effluent by FTWs at large scales.

Histone acetylation is an important epigenetic modification that regulates gene activity in response to stress. Histone acetylation levels are reversibly regulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs). The imperative roles of HDACs in gene transcription, transcriptional regulation, growth and responses to stressful environment have been widely investigated in Arabidopsis. However, data regarding HDACs in kenaf crop has not been disclosed yet. In this study, six HDACs genes (HcHDA2, HcHDA6, HcHDA8, HcHDA9, HcHDA19, and HcSRT2) were isolated and characterized. Phylogenetic tree revealed that these HcHDACs shared high degree of sequence homology with those of Gossypium arboreum. Subcellular localization analysis showed that GFP-tagged HcHDA2 and HcHDA8 were predominantly localized in the nucleus, HcHDA6 and HcHDA19 in nucleus and cytosol. The HcHDA9 was found in both nucleus and plasma membranes. Real-time quantitative PCR showed that the six HcHDACs genes were expressed with distinct expression patterns across plant tissues. Furthermore, we determined differential accumulation of HcHDACs transcripts under salt and drought treatments, indicating that these enzymes may participate in the biological process under stress in kenaf. Finally, we showed that the levels of histone H3 and H4 acetylation were modulated by salt and drought stress in kenaf. We have isolated and characterized six HDACs genes from kenaf. These data showed that HDACs are imperative players for growth and development as well abiotic stress responses in kenaf.

Growth and physiological responses of cotton (Gossypium hirsutum L.) cultivars with different phosphorus (P) efficiencies under variable P environment are poorly known. Therefore, this study explored effects of normal P [P⁺, 70 kg(P₂O₅) ha^-1] and without P (P^-, 0 kg ha^-1) on yield, growth, and physiology of different P-efficient cultivars [low-efficient Xinluzao 13 (L₁) and Xinluzao 26 (L₂); medium-efficient Xinluzao 10 (M₁) and Xinluzao 24 (M₂); high-efficient Zhongmiansuo 42 (H₁) and Xinluzao19 (H₂)]. Cotton growth and yield was higher in H₁ and H₂ cultivars under P⁺ compare to P^-. Leaf photosynthesis, intercellular CO₂ concentration, stomatal conductance, and net assimilation rate increased under P⁺ and in high-efficient cultivars. Greater Rubisco activity and higher soluble sugar content further promoted P uptake and utilization efficiency which resulted in a higher yield under normal P⁺ than that at P^- treatment. High_-P_-efficient cultivars have the potential to increase the yield by improving cotton growth and physiological attributes under P⁺.