From Genetics to Functional Genomics: Improvement in Drought Signaling and Tolerance in Wheat

Abstract

Drought being a yield limiting factor has become a major threat to international food security. It is a complex trait and drought tolerance response is carried out by various genes, transcription factors (TFs), microRNAs (miRNAs), hormones, proteins, co-factors, ions, and metabolites. This complexity has limited the development of wheat cultivars for drought tolerance by classical breeding. However, attempts have been made to fill the lost genetic diversity by crossing wheat with wild wheat relatives. In recent years, several molecular markers including single nucleotide polymorphisms (SNPs) and quantitative trait loci (QTLs) associated with genes for drought signaling pathways have been reported. Screening of large wheat collections by marker assisted selection (MAS) and transformation of wheat with different genes/TFs has improved drought signaling pathways and tolerance. Several miRNAs also provide drought tolerance to wheat by regulating various TFs/genes. Emergence of OMICS techniques including transcriptomics, proteomics, metabolomics, and ionomics has helped to identify and characterize the genes, proteins, metabolites, and ions involved in drought signaling pathways. Together, all these efforts helped in understanding the complex drought tolerance mechanism. Here, we have reviewed the advances in wide hybridization, MAS, QTL mapping, miRNAs, transgenic technique, genome editing system, and above mentioned functional genomics tools for identification and utility of signaling molecules for improvement in wheat drought tolerance.

Evolution and Adaptation of Wild Emmer Wheat Populations to Biotic and Abiotic Stresses

“…Effective dissection of drought-adaptive mechanisms at the cellular and molecular levels requires the integration of sophisticated functional genomics approaches, such as transcriptomics, metabolomics, and proteomics (15,37). Several studies were conducted in an attempt to unravel molecular mechanisms of adaptation to drought in DIC by comparing the transcriptome and metabolome profiles of genotypes contrasting in tolerance to drought stress [drought-resistant (R) versus drought-susceptible (S)], selected after screening of DIC populations from Israel and Turkey (31,65,66,104).…”

Improved drought tolerance in wheat is required to unlock the production potential of the Brazilian Cerrado

“…There are reviews focusing on drought tolerance traits in wheat and the underlying molecular mechanisms (for example, Budak et al 2015, Sheoran et al 2016, Mohammadi 2018. Here, we do not intend to be repetitive and to exhaustively review these traits and their molecular basis.…”

Association mapping of drought tolerance indices in wheat: QTL-rich regions on chromosome 4A

“…In fact, the negative effects of drought could be overcome by the identification and use of drought-tolerant varieties (Van Oosten et al, 2016). Given this solution, the dissection of molecular mechanisms that underlie adaptive traits represents one approach to understanding stress tolerance in plants (Budak et al, 2015;Liu et al, 2017;Arriagada et al, 2017). For example, Merchuk-Ovnat et al (2016) showed that the introgression of QTLs on chromosomes 1B and 2B of T. turgidum into T. aestivum can enhance drought tolerance in domesticated wheat.…”