Agronomy Department, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China.
Special Plant Genomics Laboratory, College of Life Sciences, University of Shihezi, Shihezi, Xinjiang, China.
J Exp Bot. 2018 Apr 27;69(10):2543-2553. doi: 10.1093/jxb/ery093.
In cotton, the formation of fruiting branches affects both plant architecture and fiber yield. Here, we report map-based cloning of the axillary flowering mutation gene (GbAF) that causes bolls to be borne directly on the main plant stem in Gossypium barbadense, and of the clustered boll mutation gene (cl1) in G. hirsutum. Both mutant alleles were found to represent point mutations at the Cl1 locus. Therefore, we propose that the GbAF mutation be referred to as cl1b. These Cl1 loci correspond to homologs of tomato SELF-PRUNING (SP), i.e. Gossypium spp. SP (GoSP) genes. In tetraploid cottons, single monogenic mutation of either duplicate GoSP gene (one in the A and one in the D subgenome) is associated with the axillary cluster flowering phenotype, although the shoot-indeterminate state of the inflorescence is maintained. By contrast, silencing of both GoSPs leads to the termination of flowering or determinate plants. The architecture of axillary flowering cotton allows higher planting density, contributing to increased fiber yield. Taken together the results provide new insights into the underlying mechanism of branching in cotton species, and characterization of GoSP genes may promote the development of compact cultivars to increase global cotton production.
在棉花中，结果枝的形成既影响植物的结构，也影响纤维的产量。本研究报告了导致在巴旦木棉中直接在主茎上结铃的腋生开花突变基因（GbAF）和在陆地棉中丛生棉突变基因（cl1）的图位克隆。两个突变等位基因均在 Cl1 基因座上发现了点突变。因此，我们建议将 GbAF 突变命名为 cl1b。这些 Cl1 基因座与番茄自剪（SELF-PRUNING，SP）基因同源，即棉属 spp. SP（GoSP）基因。在四倍体棉中，两个 GoSP 基因（一个在 A 亚基因组，一个在 D 亚基因组）的单一单基因突变与腋生丛生开花表型相关，尽管花序的不定梢状态得以维持。相比之下，两个 GoSP 基因的沉默导致开花终止或植株变为有限生长。腋生开花棉的结构允许更高的种植密度，从而增加纤维产量。综上所述，这些结果为棉花分枝的潜在机制提供了新的见解，GoSP 基因的鉴定可能有助于开发紧凑品种以提高全球棉花产量。
