Genetic variation in CaTIFY4b contributes to drought adaptation in chickpea

Abstract

Chickpea production is vulnerable to drought stress. Identifying the genetic components underlying drought adaptation is crucial for enhancing chickpea productivity. Here, we present the fine mapping and characterization of 'QTL-hotspot', a genomic region controlling chickpea growth with positive consequences on crop production under drought. We report that a nonsynonymous substitution in the transcription factor CaTIFY4b regulates seed weight and organ size in chickpea. Ectopic expression of CaTIFY4b in Medicago truncatula enhances root growth under water deficit. Our results suggest that allelic variation in 'QTL-hotspot' improves preanthesis water use, transpiration efficiency, root architecture and canopy development, enabling high-yield performance under terminal drought conditions. Gene expression analysis indicated that CaTIFY4b may regulate organ size under water deficit by modulating the expression of GRF-INTERACTING FACTOR1 (GIF1), a transcriptional co-activator of Growth-Regulating Factors. Taken together, our study offers new insights into the role of CaTIFY4b and on diverse physiological and molecular mechanisms underpinning chickpea growth and production under specific drought scenarios.

Genetic mapping of QTLs for drought tolerance in chickpea (Cicer arietinum L.)

“…Previous studies show that root traits, such as root length density, root depth, and root dry weight, could be promising for improving drought tolerance in chickpea (Kashiwagi et al, 2006;Zaman-Allah et al, 2011;Purushothaman et al, 2017;Barmukh et al, 2022). The present study also showed that root length density was non-significantly affected by drought stress.…”

“…Drought represents one of the most significant abiotic stresses that causes up to a 60% reduction in chickpea yields (Kumar et al, 2015;Hajjarpoor et al, 2018;Barmukh et al, 2022). Drought tolerance is highly influenced by several parameters such as days to germination, days to 50% flowering, days to maturity, biomass, and yield as morphological traits; transpiration efficiency, membrane permeability, and relative leaf water content as physiological traits; and root depth, root length density, root weight, and root to shoot ratio as root-related traits (Varshney et al, 2011).…”

“…The estimated size of this "QTL hotspot" was refined from 29 cM to 14 cM using a genotyping-by-sequencing approach (Jaganathan et al, 2015) and then to ~300 kb using a bin mapping approach (Kale et al, 2015). Notably, fine mapping of the "QTL-hotspot" region led to the identification of CaTIFY4b as the candidate gene regulating drought responses in chickpea (Barmukh et al, 2022). In the recent past, introgression of the "QTL-hotspot" region into different genetic backgrounds of elite cultivars led to the development and release of molecular breeding lines with enhanced drought tolerance (Varshney et al, 2013b;Bharadwaj et al, 2021).…”

“…In spite of its economic importance and its role in improving human health, chickpea production is falling short of meeting the dietary needs of the burgeoning human population, mainly because of low productivity due to biotic and abiotic constraints (Thudi et al, 2014;Roorkiwal et al, 2020;Kushwah et al, 2021a). Among the abiotic stresses, drought alone causes up to 60% of annual yield losses in chickpea (Sabaghpour et al, 2006;Toker et al, 2007;Varshney et al, 2010;Hajjarpoor et al, 2018;Barmukh et al, 2022). The impact of global warming and climate change has emphasized researchers' need to study the effect of drought stress on crop development and yield.…”

“…In general, it is a terminal drought that can terminate or reduce the reproductive phase to drastically reduce the crop yield. Drought tolerance is a complex quantitative trait affected by significant genotype by environment (G × E) interactions (Kashiwagi et al, 2008;Varshney et al, 2014;Barmukh et al, 2022), which hampers direct selection of genotypes with higher yield under drought conditions. Drought stress is well-known for reducing crop growth, thus affecting yield components, such as total biomass, pod number, seed number, seed weight, seed quality, and yield per plant (Toker et al, 2007;Krishnamurthy et al, 2013).…”