Overexpression of HVA1 Enhances Drought and Heat Stress Tolerance in Triticum aestivum Doubled Haploid Plants

Abstract

Plant responses to multiple environmental stresses include various signaling pathways that allow plant acclimation and survival. Amongst different stresses, drought and heat stress severely affect growth and productivity of wheat. HVA1, a member of the group 3 LEA protein, has been well known to provide protection against drought stress. However, its mechanism of action and its role in other stresses such as heat remain unexplored. In this study, doubled haploid (DH) wheat plants overexpressing the HVA1 gene were analyzed and found to be both drought-and heat stress-tolerant. The transcriptome analysis revealed the upregulation of transcription factors such as DREB and HsfA6 under drought and heat stress, respectively, which contribute toward the tolerance mechanism. Particularly under heat stress conditions, the transgenic plants had a lower oxidative load and showed enhanced yield. The overexpression lines were found to be ABA-sensitive, therefore suggesting the role of HsfA6 in providing heat tolerance via the ABA-mediated pathway. Thus, apart from its known involvement in drought stress, this study highlights the potential role of HVA1 in the heat stress signaling pathway. This can further facilitate the engineering of multiple stress tolerance in crop plants, such as wheat.

Wheat ocs-Element Binding Factor 1 Enhances Thermotolerance by Modulating the Heat Stress Response Pathway

“…On the other hand, levels of OsHsfA2, OsHSP100, OsSOD , and OsHSP90 were observed to be higher in rice transgenics after exposure to heat stress ( Figure 10 ). The role of these marker genes in attributing to thermotolerance has been reported earlier (Jacob et al, 2017 ; Samtani et al, 2022 ). Also, it is worth noticing that overexpression of TaSTI and TaHSP90 has been documented to promote thermotolerance and TaSTI overexpression lines of Arabidopsis had higher levels of AtHsfA2 and AtHsfA6 transcripts under heat stress conditions (Vishwakarma et al, 2018 ; Meena et al, 2020 ).…”

“…For vizualization the ROS levels in TaOBF1-5B Arabidopsis overexpression lines and WT, staining with nitro blue tetrazolium (NBT) was done (Meena et al, 2020 ; Samtani et al, 2022 ). The seeds were germinated on half strength MS medium and then 1- and 2-week-old plants were subjected to 42°C for 2 h, after which the overnight staining of the seedlings was done with NBT (2 mM NBT powder, 20 mM phosphate buffer).…”

Drought Stress Priming Improved the Drought Tolerance of Soybean

“…For example, we observed a strong induction of the LEA protein-encoding gene in the second stress cycle. LEA protein overexpressing transgenic lines had lower ROS, higher total chlorophyll content, and higher drought tolerance in other plants [ 44 , 45 , 46 ]. In soybean, lower ROS content and higher chlorophyll content are associated with a more tolerant genotype [ 47 ].…”

Plant Protein Disorder: Spatial Regulation, Broad Specificity, Switch of Signaling and Physiological Status

“…During the late stages of seed maturation, a group of IDPs known as LATE EMBRYOGENESIS ABUNDANT (LEA) proteins are highly expressed in plant seeds before they enter the desiccation phase (Tunnacliffe and Wise, 2007 ; Leprince et al, 2017 ), for a strong suggestion of the roles of LEA proteins in desiccation tolerance (Hincha and Thalhammer, 2012 ). In vegetative tissues, LEA proteins are induced by abiotic stresses such as drought, salinity, heat and freezing (Hincha and Thalhammer, 2012 ), as noted by the overexpression of LEA proteins often conferring stress tolerance (Samtani et al, 2022 ). The analysis of LEA proteins in Arabidopsis, tomato and orchid revealed their wide subcellular distribution (Candat et al, 2014 ; Cao and Li, 2015 ; Ling et al, 2016 ), which suggests that their ubiquitous expression would provide protection to the corresponding membranes of various organelles as well as enzymes and sequestering targets localized in different cellular compartments under certain stress conditions (Tunnacliffe and Wise, 2007 ; Candat et al, 2014 ; Artur et al, 2019 ).…”