Genetic interactions between diverged alleles of Early heading date 1 (Ehd1) and Heading date 3a (Hd3a)/ RICE FLOWERING LOCUS T1 (RFT1) control differential heading and contribute to regional adaptation in rice (Oryza sativa). Issue 3 (11th June 2015)

• Record Type: Journal Article
• Authors: Zhao, Jing; Chen, Hongyi; Ren, Ding; Tang, Huiwu; Qiu, Rong; Feng, Jinglei; Long, Yunming; Niu, Baixiao; Chen, Danping; Zhong, Tianyu; Liu, Yao‐Guang; Guo, Jingxin
• Is Part Of: New phytologist. Volume 208:Issue 3(2015:Dec. 01)
• Page Start: 936
• Page End: 948
• Publication Date: 2015-06-11
• Subjects: Botany -- Periodicals; 580
• DOI: 10.1111/nph.13503
• Languages: English
• ISSNs: 0028-646X

Abstract

<abstract abstract-type="main" id="nph13503-abs-0001"> <title>Summary</title> <p> <list id="nph13503-list-0001" list-type="bullet"> <list-item> <p>Initiation of flowering, also called heading, in rice (<italic>Oryza sativa</italic>) is determined by the florigens encoded by <italic>Heading date 3a</italic> (<italic>Hd3a</italic>) and <italic>RICE FLOWERING LOCUS T1</italic> (<italic>RFT1</italic>). <italic>Early heading date 1</italic> (<italic>Ehd1</italic>) regulates <italic>Hd3a</italic> and <italic>RFT1</italic>. However, different rice varieties have diverged alleles of <italic>Ehd1</italic> and <italic>Hd3a/RFT1</italic> and their genetic interactions remain largely unclear.</p> </list-item> <list-item> <p>Here we generated three segregating populations for different combinations of diverged <italic>Ehd1</italic> and <italic>Hd3a/RFT1</italic> alleles, and analyzed their genetic interactions between these alleles. We demonstrated that, in an <italic>ehd1</italic> mutant background, <italic>Hd3a</italic> was silenced, but <italic>RFT1</italic> was expressed (although at lower levels than in plants with a functional <italic>Ehd1</italic>) under short‐day (SD) and long‐day (LD) conditions.</p> </list-item> <list-item> <p>We identified a nonfunctional <italic>RFT1</italic> allele (<italic>rft1</italic>); the lines carrying homozygous <italic>ehd1</italic> and <italic>Hd3a/rft1</italic> failed to induce the floral transition under SD and LD conditions. Like Hd3a, RFT1 also interacted with 14‐3‐3 proteins, the florigen receptors, but a nonfunctional RFT1 with a crucial E105K mutation failed to interact with 14‐3‐3 proteins. Furthermore, analyses of sequence variation and geographic distribution suggested that functional <italic>RFT1</italic> alleles were selected during rice adaptation to high‐latitude regions.</p> </list-item> <list-item> <p>Our results demonstrate the important roles of <italic>RFT1</italic> in rice flowering and regional adaptation.</p> </list-item> </list> </p> </abstract>