Aug 2026· Horticulturae· 0 citations· 111 references
TL;DR
By connecting stress biology with translational breeding, this review provides a framework for developing climate-resilient Brassica cultivars by synthesizing recent progress in abiotic stress tolerance from physiological, genetic, epigenetic, and multi-omics perspectives.
Abstract
Climate change is increasing the frequency and severity of abiotic stresses, including drought, salinity, waterlogging, and temperature extremes, thereby threatening the productivity and quality of Brassica crops. This review synthesizes recent progress in abiotic stress tolerance from physiological, genetic, epigenetic, and multi-omics perspectives, with an emphasis on how mechanistic discoveries can be translated into breeding decisions. We first outline the signaling hierarchy that links stress perception at the plasma membrane and cell wall interface to Ca2+ signaling, MAPK cascades, hormone crosstalk, osmotic adjustment, ROS homeostasis, and metabolic reprogramming. We then examine the genetic architecture of stress tolerance through QTL mapping, GWAS, and functional genomics, highlighting how allopolyploidy, subgenome specialization, homoeologous gene divergence, and alternative splicing create both opportunities and complications for Brassica improvement. We further evaluate how transcriptomic, epigenomic, metabolomic, and microbiome-related data are revealing regulatory complexity but remain underused for prediction and causal inference. Major bottlenecks include the inefficient conversion of association signals into validated functional markers, the descriptive rather than predictive use of multi-omics datasets, limited mechanistic understanding of combined stresses, and insufficient field validation across genetic backgrounds. Finally, we discuss integrated breeding strategies, including marker-assisted selection, genomic selection, genome editing, wild germplasm utilization, microbiome-assisted approaches, and synthetic biology. By connecting stress biology with translational breeding, this review provides a framework for developing climate-resilient Brassica cultivars.
Climate-related stresses, including drought, salinity, temperature extremes (cold and heat), and waterlogging, substantially constrain Brassica napus productivity, particularly when they occur during reproductive development or as compound stresses. Because B. napus is an allotetraploid species, stress-resilience traits are shaped by polygenic inheritance, gene redundancy, and subgenome-specific regulation. This review integrates QTL mapping, GWAS, transcriptomic evidence, and functional studies to prioritize candidate genes and pathway-level modules associated with climate-resilience. Drought and salinity candidates converge on ABA signaling, osmotic adjustment, proline biosynthesis, aquaporin-mediated water transport, and ion-homeostasis pathways, including SOS and NHX-related components. Temperature resilience is associated with CBF/DREB-mediated cold acclimation and HSF-HSP-DREB2A-linked proteostasis under heat stress. Waterlogging tolerance is linked to hypoxia and ethylene signaling, redox protection, and CIPK15/SnRK1-related energy regulation. We distinguish positional candidates from expression-supported and experimentally validated genes and discuss how these targets can be used in MAS, genomic selection, allele pyramiding, and genome editing. Current evidence supports pathway-level convergence, but causal validation of individual B. napus gene copies and evaluation of yield trade-offs remain major priorities.
R. Gill, M. Helal, Qian Xing et al.· Frontiers in Plant Science· 0 citations
This synthesis provides a framework for translating mechanistic hormonal insights into field-applicable cultivars to ensure global food security and proposes a systems-level roadmap for developing climate-resilient rice cultivars capable of maintaining yield stability across a volatile combinatorial stress landscape.
Shuixing Zhu, Zhu Jing, Dikhnah Alshehri et al.· Frontiers in Plant Science· 0 citations
Climate change increasingly exposes crops to overlapping abiotic and biotic stresses, creating a need for regulatory strategies that improve stress tolerance without imposing unnecessary fitness costs under favorable conditions. Melatonin has been widely associated with plant responses to drought, salinity, temperature extremes, oxidative stress, and pathogen challenge, where it contributes to redox balance, hormone crosstalk, and stress-responsive gene regulation. However, the benefits of melatonin appear to depend strongly on when, where, and to what extent it is produced. In this review, we examine melatonin biosynthesis and function from a promoter-centered perspective, focusing on how stress-associated signals may regulate the core biosynthetic genes TDC, T5H, SNAT, and ASMT/COMT across tissues and stress contexts. Because direct functional validation of specific promoter architectures in plant melatonin biosynthesis genes remains limited, this review presents the promoter-centered model as a hypothesis-generating framework rather than a fully established regulatory mechanism. Here, we argue that the melatonin-mediated stress tolerance depends primarily on regulated, context-dependent pathway activation rather than constitutive pathway enhancement. We therefore discuss how current knowledge of stress signaling, cis-regulatory organization, and genome editing can be used to frame future efforts in promoter engineering of melatonin biosynthesis genes. Throughout, we distinguish established findings from forward-looking hypotheses and highlight key experimental questions that must be addressed before these concepts can be translated into crop improvement.
Muhammad Hafeez Ullah Khan, Ali Muhammad, Lijie Li et al.· Journal of Pineal Research· 0 citations
Heat stress represents one of the most severe abiotic constraints to rice (
Oryza sativa
L.) productivity and is expected to intensify under ongoing climate change, particularly affecting the reproductive phase and leading to substantial yield and grain quality losses. This review synthesizes current knowledge on the impacts of heat stress on rice reproduction, with a focus on both male and female reproductive structures and their interactions. Evidence from anatomical, physiological, transcriptomic, and metabolomic studies to describe how elevated temperatures disrupt key reproductive processes, including microsporogenesis, anther dehiscence, pollen viability, pollen-pistil interactions, fertilisation, and embryo sac development were integrated in this review. It further discusses the genotype-dependent differences in reproductive thermotolerance; and key genes, metabolites, and pathways associated with heat stress perception, signalling, and tolerance are highlighted. Finally, it is briefly discussed how recent advances in breeding strategies, functional genomics and genome-editing technologies, particularly CRISPR-based approaches, are providing new opportunities to enhance reproductive resilience to heat stress and how it is essential to close the existing molecular knowledge gaps in the development of heat-tolerant rice varieties capable of sustaining productivity in a warming climate.
Miguel Moreira, Ana Rita Queirós, Ana Ventura et al.· Frontiers in Genome Editing· 0 citations
Salt and heat stresses often occur simultaneously in arid regions, restricting the distribution and productivity of alfalfa (Medicago sativa L.). However, the mechanisms underlying alfalfa responses to combined salt and heat stress remain unclear. Here, we integrated phenotypic, physiological, transcriptomic, and metabolomic analyses to investigate the regulatory mechanisms involved in combined stress responses. Combined stress more strongly inhibited plant height, stem diameter, fresh weight, net photosynthetic rate, and transpiration rate than single stresses. Salt stress had a predominant effect on several agronomic and physiological traits, whereas heat stress mainly affected chloroplast ultrastructure. Multiomics analysis identified flavonoid metabolism, linoleic acid metabolism, and amino acid biosynthesis as key pathways associated with combined stress responses. Moreover, CHS, CHR, P5CS, and LOX genes expression was closely correlated with metabolites such as naringenin, naringenin chalcone, and proline. These findings provide insights into alfalfa adaptation to multiple abiotic stresses.
Lihe Su, Yongcheng Chen, Xudong Zhang et al.· Journal of Agricultural and...· 0 citations
Abiotic stresses increasingly threaten crop productivity, whereas reliance on chemical and resource-intensive interventions can compromise environmental sustainability. Existing literature identifies Trichoderma spp. as multifunctional biocontrol agents, biofertilizers, and microbial biostimulants capable of influencing plant growth, stress signaling, and rhizosphere processes; however, evidence remains fragmented across strains, crops, formulations, and stress conditions. This review aimed to integrate current knowledge on Trichoderma-mediated resilience to salinity, drought, heavy metals, temperature extremes, and emerging pollutants, while distinguishing experimentally validated mechanisms from statistical associations and conceptual inference. It evaluates constraints governing reproducibility from controlled studies to field deployment. The synthesis shows that selected crop–strain systems improve root architecture, photosynthesis, antioxidant regulation, osmotic adjustment, nutrient acquisition, ion homeostasis, hormonal balance, and stress-responsive gene expression. Benefits arise through coordinated delivery, root colonization, metabolite and protein signaling, physiological reprogramming, and rhizosphere modulation. Nevertheless, microbiome co-occurrence patterns do not establish causal network repair, evidence for broad heat and cold protection remains limited, and biochar co-application should not be interpreted as a carrier formulation without direct validation. Future progress requires strain- and crop-specific screening, mechanistic gene and protein studies, standardized formulations, combined-stress experiments, multi-location field trials, biosafety evaluation, and farmer-level economic assessment to develop reliable precision microbial technologies.
Xueping Su, Fang Qin, Cheng Huang et al.· Journal of Fungi· 0 citations
A new method for surgically removing training examples from a model reveals that as datasets grow, the link between what a model learns and what it produces dissolves.
