QTL detection and putative candidate gene prediction for leaf rolling under moisture stress condition in wheat

Abstract

Leaf rolling is an important mechanism to mitigate the effects of moisture stress in several plant species. In the present study, a set of 92 wheat recombinant inbred lines derived from the cross between NI5439 × HD2012 were used to identify QTLs associated with leaf rolling under moisture stress condition. Linkage map was constructed using Axiom 35 K Breeder’s SNP Array and microsatellite (SSR) markers. A linkage map with 3661 markers comprising 3589 SNP and 72 SSR markers spanning 22,275.01 cM in length across 21 wheat chromosomes was constructed. QTL analysis for leaf rolling trait under moisture stress condition revealed 12 QTLs on chromosomes 1B, 2A, 2B, 2D, 3A, 4A, 4B, 5D, and 6B. A stable QTL Qlr.nhv-5D.2 was identified on 5D chromosome flanked by SNP marker interval AX-94892575–AX-95124447 (5D:338665301–5D:410952987). Genetic and physical map integration in the confidence intervals of Qlr.nhv-5D.2 revealed 14 putative candidate genes for drought tolerance which was narrowed down to six genes based on in-silico analysis. Comparative study of leaf rolling genes in rice viz., NRL1, OsZHD1, Roc5, and OsHB3 on wheat genome revealed five genes on chromosome 5D. Out of the identified genes, TraesCS5D02G253100 falls exactly in the QTL Qlr.nhv-5D.2 interval and showed 96.9% identity with OsZHD1. Two genes similar to OsHB3 viz. TraesCS5D02G052300 and TraesCS5D02G385300 exhibiting 85.6% and 91.8% identity; one gene TraesCS5D02G320600 having 83.9% identity with Roc5 gene; and one gene TraesCS5D02G102600 showing 100% identity with NRL1 gene were also identified, however, these genes are located outside Qlr.nhv-5D.2 interval. Hence, TraesCS5D02G253100 could be the best potential candidate gene for leaf rolling and can be utilized for improving drought tolerance in wheat.

A digital sensor to measure real-time leaf movements and detect abiotic stress in plants

“…The effect of drought on diurnal leaf movements is less studied, except for some reports on the enhanced paraheliotropic response in banana laminae ( Thomas and Turner, 2001 ; Stevens et al, 2020 ) and leaf rolling in maize ( Baret et al, 2018 ). Both of these movements are, however, important indicators of drought stress, also observed in other monocot species such as wheat ( Verma et al, 2020 ) and rice ( Cal et al, 2019 ) and are determined mainly by leaf morphology ( Cal et al, 2019 ). Our analysis of leaf movements during water-deficit stress in M. balbisiana , a drought resilient banana genotype ( Van Wesemael et al, 2018 ), originating from drought-prone regions ( Perrier et al, 2011 ; Kissel et al, 2015 ; Eyland et al, 2021) , showed less lamina folding compared to two M. acuminata genotypes, indicating that M. balbisiana is less responsive toward dry conditions ( Figure 5 ).…”

Identification and Fine Mapping of a Locus Related to Leaf Up-Curling Trait (Bnuc3) in Brassica napus

“…Moderate leaf curling minimizes shadowing between leaves and improves crop yield by increasing planting density [45,46]. It also reduces leaf transpiration under drought stress [47]. Therefore, studies on leaf living states are of significance.…”

Drought Tolerance Strategies and Autophagy in Resilient Wheat Genotypes

“…This is due to quantitative genetic control with many small-contributing loci, inconsistent quantitative trait loci (QTL), strong genotype x environment interactions, and low heritability [ 7 , 8 ]. Genomic-wide association studies (GWAS) can identify and map candidate genes to be used as breeding markers with greater precision [ 9 , 10 , 11 , 12 ]. Therefore, expanding the list of genetic markers for physiological, morphological, and molecular survival mechanisms is essential for breeding drought-resilient varieties.…”