TaUBA, a UBA domain-containing protein in wheat (Triticum aestivum L.), is a negative regulator of salt and drought stress response in transgenic Arabidopsis

Insights into Salinity Tolerance in Wheat

Salt stress has a detrimental impact on food crop production, with its severity escalating due to both natural and man-made factors. As one of the most important food crops, wheat is susceptible to salt stress, resulting in abnormal plant growth and reduced yields; therefore, damage from salt stress should be of great concern. Additionally, the utilization of land in coastal areas warrants increased attention, given diminishing supplies of fresh water and arable land, and the escalating demand for wheat. A comprehensive understanding of the physiological and molecular changes in wheat under salt stress can offer insights into mitigating the adverse effects of salt stress on wheat. In this review, we summarized the genes and molecular mechanisms involved in ion transport, signal transduction, and enzyme and hormone regulation, in response to salt stress based on the physiological processes in wheat. Then, we surveyed the latest progress in improving the salt tolerance of wheat through breeding, exogenous applications, and microbial pathways. Breeding efficiency can be improved through a combination of gene editing and multiple omics techniques, which is the fundamental strategy for dealing with salt stress. Possible challenges and prospects in this process were also discussed.

Acclimation response and management strategies to combat heat stress in wheat for sustainable agriculture: A state-of-the-art review

Unpredicted variability in climate change on the planet is associated with frequent extreme high-temperature events impacting crop yield globally. Wheat is an economically and nutritionally important crop that fulfils global food requirements and each degree rise in temperature results in ∼6% of its yield reduction. Thus, understanding the impact of climate change, especially the terminal heat stress on global wheat production, becomes critically important for policymakers, crop breeders, researchers and scientists to ensure global food security. This review describes how wheat perceives heat stress and induces stress adaptation events by its morpho-physiological, phenological, molecular, and biochemical makeup. Temperature above a threshold level in crop vicinity leads to irreversible injuries, viz. destruction of cellular membranes and enzymes, generation of active oxygen species, redox imbalance, etc. To cope with these changes, wheat activates its heat tolerance mechanisms characterized by hoarding up soluble carbohydrates, signalling molecules, and heat tolerance gene expressions. Being vulnerable to heat stress, increasing wheat production without delay seeks strategies to mitigate the detrimental effects and provoke the methods for its sustainable development. Thus, to ensure the crop's resilience to stress and increasing food demand, this article circumscribes the integrated management approaches to enhance wheat's performance and adaptive capacity besides its alleviating risks of increasing temperature anticipated with climate change. Implementing these integrated strategies in the face of risks from rising temperatures will assist us in producing sustainable wheat with improved yield.

Wheat adaptation to environmental stresses under climate change: Molecular basis and genetic improvement

Wheat (Triticum aestivum) is a staple food for about 40% of the world's population. As the global population has grown and living standards improved, high yield and improved nutritional quality have become the main targets for wheat breeding. However, wheat production has been compromised by global warming through the more frequent occurrence of extreme temperature events, which have increased water scarcity, aggravated soil salinization, caused plants to be more vulnerable to diseases, and directly reduced plant fertility and suppressed yield. One promising option to address these challenges is the genetic improvement of wheat for enhanced resistance to environmental stress. Several decades of progress in genomics and genetic engineering has tremendously advanced our understanding of the molecular and genetic mechanisms underlying abiotic and biotic stress responses in wheat. These advances have heralded what might be considered a "golden age" of functional genomics for the genetic improvement of wheat. Here, we summarize the current knowledge on the molecular and genetic basis of wheat resistance to abiotic and biotic stresses, including the QTLs/genes involved, their functional and regulatory mechanisms, and strategies for genetic modification of wheat for improved stress resistance. In addition, we also provide perspectives on some key challenges that need to be addressed.

Comparative Ubiquitination Proteomics Revealed the Salt Tolerance Mechanism in Sugar Beet Monomeric Additional Line M14

Post-translational modifications (PTMs) are important molecular processes that regulate organismal responses to different stresses. Ubiquitination modification is not only involved in human health but also plays crucial roles in plant growth, development, and responses to environmental stresses. In this study, we investigated the ubiquitination proteome changes in the salt-tolerant sugar beet monomeric additional line M14 under salt stress treatments. Based on the expression of the key genes of the ubiquitination system and the ubiquitination-modified proteins before and after salt stress, 30 min of 200 mM NaCl treatment and 6 h of 400 mM NaCl treatment were selected as time points. Through label-free proteomics, 4711 and 3607 proteins were identified in plants treated with 200 mM NaCl and 400 mM NaCl, respectively. Among them, 611 and 380 proteins were ubiquitinated, with 1085 and 625 ubiquitination sites, in the two salt stress conditions, respectively. A quantitative analysis revealed that 70 ubiquitinated proteins increased and 47 ubiquitinated proteins decreased. At the total protein level, 42 were induced and 20 were repressed with 200 mM NaCl, while 28 were induced and 27 were repressed with 400 mM NaCl. Gene ontology, KEGG pathway, protein interaction, and PTM crosstalk analyses were performed using the differentially ubiquitinated proteins. The differentially ubiquitinated proteins were mainly involved in cellular transcription and translation processes, signal transduction, metabolic pathways, and the ubiquitin/26S proteasome pathway. The uncovered ubiquitinated proteins constitute an important resource of the plant stress ubiquitinome, and they provide a theoretical basis for the marker-based molecular breeding of crops for enhanced stress tolerance.

UBA domain protein SUF1 interacts with NatA-complex subunit NAA15 to regulate thermotolerance in Arabidopsis

During recovery from heat stress, plants clear away the heat-stress-induced misfolded proteins through the ubiquitin-proteasome system (UPS). In the UPS, the recognition of substrate proteins by E3 ligase can be regulated by the N-terminal acetyltransferase A (NatA) complex. Here, we determined that Arabidopsis STRESS-RELATED UBIQUITIN-ASSOCIATED-DOMAIN PROTEIN FACTOR 1 (SUF1) interacts with the NatA complex core subunit NAA15 and positively regulates NAA15. The suf1 and naa15 mutants are sensitive to heat stress; the NatA substrate ^N SNC1 is stabilized in suf1 mutant plants during heat stress recovery. Therefore, SUF1 and its interactor NAA15 play important roles in basal thermotolerance in Arabidopsis.

Genome-Wide Identification and Evolutionary Analysis of Gossypium Tubby-Like Protein (TLP) Gene Family and Expression Analyses During Salt and Drought Stress

Tubby-like proteins (TLPs) possess a highly conserved closed β barrel tubby domain at C-terminal and N-terminal F-box. The role of TLP gene family members has been widely discussed in numerous organisms; however, the detailed genome-wide study of this gene family in Gossypium species has not been reported till date. Here, we systematically identified 105 TLP gene family members in cotton (Gossypium arboreum, Gossypium raimondii, Gossypium hirsutum, and Gossypium barbadense) genomes and classified them into eight phylogenetic groups. Cotton TLP12 gene family members clustered into two groups, 4 and 8. They experienced higher evolutionary pressure in comparison to others, indicating the faster evolution in both diploid as well as in tetraploid cotton. Cotton TLP gene family members expanded mainly due to segmental duplication, while only one pair of tandem duplication was found in cotton TLPs paralogous gene pairs. Subsequent qRT-PCR validation of seven putative key candidate genes of GhTLPs indicated that GhTLP11A and GhTLP12A.1 genes were highly sensitive to salt and drought stress. The co-expression network, pathways, and cis-regulatory elements of GhTLP11A and GhTLP12A.1 genes confirmed their functional importance in salt and drought stress responses. This study proposes the significance of GhTLP11A and GhTLP12A.1 genes in exerting control over salt and drought stress responses in G. hirsutum and also provides a reference for future research, elaborating the biological roles of G. hirsutum TLPs in both stress responses.

Isolation and identification of wheat gene TaDIS1 encoding a RING finger domain protein, which negatively regulates drought stress tolerance in transgenic Arabidopsis

Drought stress is a major factor that limits the yield and quality in wheat. In this study, we identified an orthologue of the rice gene OsDIS1 (Oryza sativa drought-induced SINA protein 1) in wheat (Triticum aestivum L.) called TaDIS1. TaDIS1 encodes a putative 301 amino acid protein with a C3HC4 RING finger conserved domain at the N-terminal and a SINA domain at the C-terminal. TaDIS1 contains three exons and two introns. qRT-PCR analysis showed that TaDIS1 expression was induced by PEG6000, NaCl, and abscisic acid (ABA) treatment. We generated TaDIS1-overexpressing transgenic Arabidopsis lines. Under drought stress conditions, the transgenic Arabidopsis plants had a lower germination rate, relative water content, and proline contents, with higher water loss, chlorophyll loss, relative electrical conductivity, and malondialdehyde contents compared with the wild type. The antioxidant enzyme (superoxide dismutase, peroxidase, and catalase) activity levels were lower in the transgenic plants. The TaDIS1-overexpressing plants had shorter roots with greater growth inhibition in response to mannitol treatment than the wild type, with increased hypersensitivity to ABA during seed germination and early seedling growth. The expression of stress-related genes in transgenic plants under drought stress suggests that TaDIS1 may function negatively in drought stress by regulating the stress response-related genes.