State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China.
Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China.
Mol Plant. 2020 Jun 1;13(6):923-932. doi: 10.1016/j.molp.2020.03.009. Epub 2020 Mar 25.
Plant architecture is a complex agronomic trait and a major factor of crop yield, which is affected by several important hormones. Strigolactones (SLs) are identified as a new class hormoneinhibiting branching in many plant species and have been shown to be involved in various developmental processes. Genetical and chemical modulation of the SL pathway is recognized as a promising approach to modify plant architecture. However, whether and how the genes involved in the SL pathway could be utilized in breeding still remain elusive. Here, we demonstrate that a partial loss-of-function allele of the SL biosynthesis gene, HIGH TILLERING AND DWARF 1/DWARF17 (HTD1/D17), which encodes CAROTENOID CLEAVAGE DIOXYGENASE 7 (CCD7), increases tiller number and improves grain yield in rice. We found that the HTD1 gene had been widely utilized and co-selected with Semidwarf 1 (SD1), both contributing to the improvement of plant architecture in modern rice varieties since the Green Revolution in the 1960s. Understanding how phytohormone pathway genes regulate plant architecture and how they have been utilized and selected in breeding will lay the foundation for developing the rational approaches toward improving crop yield.
植物结构是一个复杂的农艺性状，也是作物产量的主要因素之一，它受到几种重要激素的影响。独脚金内酯（SLs）被确定为一种新的分支抑制激素，在许多植物物种中发挥作用，并被证明参与了各种发育过程。SL 途径的遗传和化学调节被认为是一种改良植物结构的有前途的方法。然而，参与 SL 途径的基因是否以及如何能够用于育种仍然难以捉摸。在这里，我们证明了 SL 生物合成基因 HIGH TILLERING AND DWARF 1/DWARF17（HTD1/D17）的部分功能丧失等位基因，该基因编码 CAROTENOID CLEAVAGE DIOXYGENASE 7（CCD7），可增加水稻分蘖数并提高产量。我们发现，自 20 世纪 60 年代绿色革命以来，HTD1 基因与半矮秆 1（SD1）一起被广泛利用和共同选择，这两者都有助于改良现代水稻品种的植物结构。了解植物激素途径基因如何调节植物结构，以及它们在育种中是如何被利用和选择的，将为开发提高作物产量的合理方法奠定基础。
