title: A dominant major locus in chromosome 9 of rice (Oryza sativa L.) confers tolerance to 48°C high temperature at seedling stage.
abstract: In an earlier greenhouse screening, we identified a local indica cultivar HT54 tolerant to high temperature at both seedling and grain-filling stages. In this study, we develop an optimized procedure for fine assessment of this heat tolerance. The results indicated that HT54 seedlings could tolerate high temperature up to 48 °C for 79h. The genetic analysis of F(1) and F(2) offspring derived from the cross between HT54 and HT13, a heat-sensitive breeding line, reveals that the heat tolerance of HT54 was controlled by a dominant major locus, which has been designated as OsHTAS (Oryza sativa heat tolerance at seedling stage). This locus was mapped on rice chromosome 9 within an interval of 420kb between markers of InDel5 and RM7364. The determined candidate ZFP gene has been confirmed to be cosegregated with a single nucleotide polymorphism (SNP) developed PCR-restriction fragment length polymorphism (RFLP) marker RBsp1407 in its promoter region. Another heat tolerance-associated SNP was identified in the first intron of its 5'-untranslated region. The existence of these SNPs thereby indicated that the OsHTAS locus contains at least two alleles. We named the one from HT54 as OsHTAS  (  a  ) and the one from HT13 as OsHTAS  (  b  ). Further dynamic expression analysis demonstrated that OsHTAS  (  a  ) was actively responsive to 45 °C high temperature stress compared with the OsHTAS  (  b  ) allele.
authors.affiliation: Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University,  Yuhangtang Road 388, Hangzhou 310058, China.
authors.forename: He
authors.initials: H
authors.lastname: Wei
authors.forename: Jianping
authors.initials: J
authors.lastname: Liu
authors.forename: Ya
authors.initials: Y
authors.lastname: Wang
authors.forename: Nongrong
authors.initials: N
authors.lastname: Huang
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Zhang
authors.forename: Liangchao
authors.initials: L
authors.lastname: Wang
authors.forename: Jiwen
authors.initials: J
authors.lastname: Zhang
authors.forename: Jumin
authors.initials: J
authors.lastname: Tu
authors.forename: Xuhua
authors.initials: X
authors.lastname: Zhong
mesh_terms: D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D018506:Gene Expression Regulation, Plant; D023061:Gene Order; D005799:Genes, Dominant; D017343:Genes, Plant; D023281:Genomics; D006358:Hot Temperature; D040582:Inheritance Patterns; D012275:Oryza / Q000235:genetics* / Q000254:growth & development; D019655:Quantitative Trait, Heritable; D036226:Seedlings / Q000235:genetics* / Q000254:growth & development; D013312:Stress, Physiological