Molecular characterization and functional analysis of barley semi-dwarf mutant Riso no. 9265.

Abstract

BACKGROUND:

sdw1/denso is one of the most important and useful semi-dwarf genes in barley breeding. At least four sdw1/denso alleles have been reported and HvGA20ox 2 is considered as the candidate gene. Up to date, results of studies have not univocally proven the genetic relationship between sdw1/denso and HvGA20ox 2 .

RESULTS:

In the present study, a complete deletion of Morex_contig_40861 including both HvGA20ox 2 and Mloc_56463 genes was identified at the sdw1 locus from a semi-dwarf mutant Riso no. 9265. Expression of the genes encoding gibberellin biosynthesis (HvGA20ox 1 and HvGA3ox 2 ) were increased in the mutant compared to the wild type Bomi, while the expression of GA catabolic gene HvGA2ox 3 was decreased. Over-expression of HvGA20ox 2 could rescue the semi-dwarf phenotype and increase GAs concentration.

CONCLUSIONS:

We confirmed that a GA biosynthetic enzyme HvGA20ox2, acted as GA 20-oxidase, is the functional gene for the sdw1/denso semi-dwarfism. Lose of HvGA20ox 2 is partially compensated by HvGA20ox 1 and further feedback is regulated by gibberellin. We also deduced that the sdw1/denso allele itself affects later heading owing to its reduced endogenous GAs concentration.

• Authors: Qiaojun Jia, Chengdao Li, Yi Shang, Jinghuan Zhu, Wei Hua, Junmei Wang, Jianming Yang, Guoping Zhang
• Journal: BMC genomics (BMC Genomics) Vol. 16 Pg. 927 (Nov 14 2015) ISSN: 1471-2164 [Electronic] England
• PMID: 26573602 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Topics

• Gene Deletion
• Genes, Plant
• Hordeum (anatomy & histology, genetics)
• Mutation