A wheat dominant dwarfing line with Rht12, which reduces stem cell length and affects gibberellic acid synthesis, is a 5AL terminal deletion line

Abstract

These authors contributed equally to this work. SUMMARYDwarfing and semi-dwarfing are important agronomic traits that have great potential for the improvement of wheat yields. Rht12, a dominant gibberellic acid (GA)-responsive dwarfing gene from the gamma-rayinduced wheat mutant Karcagi 522M7K, is located in the long arm of chromosome 5A, which is closely linked with the locus Xwmc410. Rht12 is likely an ideal gene for GA biosynthesis and deactivation research in common wheat. However, information on the Rht12 locus and sequence is lacking. In this study, Rht12 significantly shortened stem cell length and decreased GA biosynthetic components. Using bulked segregant RNA-Seq, wheat 660k single nucleotide polymorphism chip detection, and newly developed simple sequence repeat markers, Rht12 was mapped to a 11.21-Mb region at the terminal end of chromosome 5AL, and was found to be closely linked with the Xw5ac207 SSR marker with a 10.73-Mb fragment deletion in all of the homologous dwarfing plants. Transcriptome analyses of the remaining 483-kb region showed significantly higher expression of the TraesCS5A01G543100 gene encoding the GA metabolic enzyme GA 2-b-dioxygenase in dwarfing plants than in high stalk plants, suggesting that Rht12 reduces plant height by activating TaGA2ox-A14. Taken together, our findings will promote cloning and functional studies of Rht12 in common wheat.

Gene Expression Profiling and Fine Mapping Identifies a Gibberellin 2-Oxidase Gene Co-segregating With the Dominant Dwarfing Gene Ddw1 in Rye (Secale cereale L.)

“…This applies for instance to the UGT gene residing in the 831 -kb target interval on chromosome 5A, as the glycosylation of gibberellins provides a mechanisms to control the endogenous GA level (Ostrowski and Jakubowska, 2014). Interestingly and in contrast to the results of the present study, no difference in the expression of UGT gene TraesCS5A02G543000 has been reported between Rht12 and rht12 lines in wheat (Sun et al, 2019).…”

“…Comparative mapping identified two segments on wheat chromosomes 5A and 4B, which are orthologous to the Ddw1 locus in rye. The markers c26102 and c15679 are flanking Ddw1 and define a 831-kb segment on wheat chromosome 5A, which resides within a 11.21 Mb interval carrying the GA-sensitive dwarfing gene Rht12 in wheat (Sun et al, 2019) and which revealed perfect micro-colinearity to the Ddw1 locus (Figure 9). In total, five genes have been predicted in the 831-kb segment including TraesCS5A02G543000, a UDP Glycosyltransferase (UGT) gene, and the GA2ox gene TraesCS5A02G543100.…”

“…As described before, the UGT as well as the GA2ox gene are differentially expressed in stems of semi-dwarf and tall rye. In wheat, the marker W5AC211 delimits a 483-kb segment in the Rht12 interval proximal of a 10.73-Mb fragment deletion (Sun et al, 2019). The gene models TraesCS5A02G543000 and TraesCS5A02G543100 are located in the 531-kb region delimited by the rye marker c26102 and W5AC211 , respectively (Figure 9).…”

“…In the RIL population, heterozygous Ddw1 genotypes revealed a height reduction of 30%, which is stronger than height reduction associated with the GA-insensitive dwarfing gene Rht-B1b (−23%) in wheat but comparable to phenotypic effects of Rht13 (−34%, Rebetzke et al, 2012), a GA-sensitive dwarfing gene located on wheat chromosome 7BS (Wang et al, 2015). For the GA-sensitive dwarfing gene Rht12 residing on wheat chromosome 5AL a stronger phenotypic effect has been observed resulting in a height reduction of semi-dwarf Rht12 lines ranging between 43−49% as compared to tall rht12 genotypes (Sun et al, 2019). Testcross means for PH in highly heterozygous interpool rye hybrids ranged between 122 cm (Auinger et al, 2016) and 136 cm (Miedaner et al, 2018).…”

High-Resolution Mapping of the Novel Early Leaf Senescence Gene Els2 in Common Wheat

“…The 660K SNP array [42] has been effectively applied to develop Kompetitive allele-specific polymerase chain reaction (KASP) markers for saturation mapping of the target genes. Examples include the molecular mapping of the dwarfing genes Rht12 [43] and Rht24 [44], stripe rust resistances Yr26 [45], YrH62 [46] and Qyrnap.nwafu-2BS [47], and the chlorina mutant gene cn-A1 [48].…”