Natural variation of indels in the CTB3 promoter confers cold tolerance in japonica rice.

Improvement of cold tolerance at the booting stage (CTB) in rice is a key strategy for cultivation in high-altitude and high-latitude regions. Here, we identify CTB3 gene, encoding a calmodulin-binding transcriptional activator that positively regulates cold tolerance at the booting stage in japonica rice. Two indels (57-bp and 284-bp) in the CTB3 promoter confer a differential transcriptional response to cold between the japonica and indica subspecies.

Natural variation of CTB5 confers cold adaptation in plateau japonica rice.

During cold acclimation in high-latitude and high-altitude regions, japonica rice develops enhanced cold tolerance, but the underlying genetic basis remains unclear. Here, we identify CTB5, a homeodomain-leucine zipper (HD-Zip) transcription factor that confers cold tolerance at the booting stage in japonica rice. Four natural variations in the promoter and coding regions enhance cold response and transcriptional regulatory activity, enabling the favorable CTB5 allele to improve cold tolerance.

CTB6 Confers Cold Tolerance at the Booting Stage by Maintaining Tapetum Development in Rice.

Rice is highly sensitive to cold stress, particularly at the booting stage, which significantly threatens rice production. In this study, we cloned a gene, CTB6, encoding a lipid transfer protein involved in cold tolerance at the booting stage in rice, based on our previous fine-mapped quantitative trait locus (QTL) qCTB10-2. CTB6 is mainly expressed in the tapetum and young microspores of the anther.

QTL detection and candidate gene identification of for cold tolerance in the Yunnan plateau landrace rice.

Unlabelled: Cold stress is one of the main abiotic stresses that affects rice growth and production worldwide. Dissection of the genetic basis is important for genetic improvement of cold tolerance in rice. In this study, a new source of cold-tolerant accession from the Yunnan plateau, Lijiangxiaoheigu, was used as the donor parent and crossed with a cold-sensitive cultivar, Deyou17, to develop recombinant inbred lines (RILs) for quantitative trait locus (QTL) analysis for cold tolerance at the early seedling and booting stages in rice.