Identification and genetic analysis of EMS-mutagenized wheat mutants conferring lesion-mimic premature aging

Abstract

Background: Lesion-mimic and premature aging ( lmpa ) mutant lm pa 1 was identified from the ethyl methane sulfonate (EMS) mutant library in the bread wheat variety Keda 527 (KD527) background. To reveal the genetic basis of l mpa 1 mutant, phenotypic observations and analyses of chlorophyll content and photosynthesis were carried out in l mpa 1 , KD527 and their F 1 and F 2 derivatives. Further, bulked segregation analysis (BSA) in combination with a 660K SNP Chip were conducted on the F 2 segregation population of l mpa 1 /Chinese spring(CS) to locate the l mpa 1 gene. Results: Most agronomic traits of l mpa 1 were similar to those of KD527 before lesion-like spots appeared. Genetic analysis indicated that the F 1 plants from the crossing of l mpa 1 and KD527 exhibited the l mpa phenotype and the F 2 progenies showed a segregation of normal (wild type, WT) and l mpa , with the ratios of l mpa :WT=124:36（χ 2 =1.008<=3.841), indicating that l mpa is a dominant mutation. The combination of BSA and the SNP Chip analysis of CS, l mpa 1 and l mpa 1 /CS F 2 WT pool (50 plants) and l mpa pool (50 plants) showed that polymorphic SNPs were enriched on chromosome 5A, within a region of 30-40 Mb, indicating that the wheat premature aging gene Lmpa1 was probably located on the short arm of chromosome 5A. Conclusions: EMS-mutagenized mutant lmpa 1 deriving from elite wheat line KD527 conferred lmpa . lmpa phenotype of l mpa 1 mutant is controlled by a single dominant allele designated as Lmpa1 , which affected wheat growth and development and reduced the thousand grain weight ( tgw ) of single plant in wheat. The gene Lmpa1 was tentatively located within the region of 30-40 Mb near to the short arm of chromosome 5A.

Current trends and insights on EMS mutagenesis application to studies on plant abiotic stress tolerance and development

“…Reverse genetics can be applied to plant tillering, regardless of the level of plant genome structure (Kurowska et al, 2011). In contrast to other reverse genetics methods (such as RNAi technology) and T-DNA insertional mutagens, this non-transgenic method does not require transformation (Krysan et al, 1999;Travella et al, 2006). TILLING aims to find nucleotide changes caused by chemical mutagenesis in target genes, to enable changes in protein function (Till et al, 2004).…”

Evaluation of Some Bread Wheat Mutants for Adult Plant Resistance to Stem Rust

“…Plant breeders have utilized diverse physical, chemical, and combination mutagens to produce genetic variation or diversity in various crops. More than 3362 cultivars obtained either as direct mutants or derived from their crosses have been released worldwide in more than 75 countries (Fatma Sarsu, et al, 2020, Xiong, et al, 2018and Kong, et al, 2020. There are 2635 varieties could be generated by physical mutagens, 398 developed by chemical mutagens, and 37 produced by a mix of physical and chemical mutagens.…”