近日，日本国立遗传学研究所Katsutoshi Tsuda等研究人员发现，YABBY和分化的KNOX1基因塑造茎中的节和节间。2024年6月14日，国际知名学术期刊《科学》发表了这一成果。

在节和节间清晰的水稻中，研究人员发现，I类knotted1-like homeobox（KNOX1）的一个亚分支负责芽分生组织的不确定性，通过抑制叶片发育的YABBY基因和另一个节特异性KNOX1亚分支的基因，限制了节的分化并允许节间的形成。YABBY促进节的维管分化并限制茎的伸长。

YABBY和节点特异性KNOX1基因指定了叶枕，叶枕进一步完善了节点结构，从而实现向心力。值得注意的是，这种KNOX1亚分支组织是种子植物所特有的。研究人员认为，节和节间是由YABBY-KNOX1交叉调节指定的不同领域，它们在早期种子植物中发生了分化。

据了解，植物茎由专门进行溶质交换和伸长的节和节间组成。然而，它们之间的界限并不明确，这些基本单位是如何产生的也仍不清楚。

附：英文原文

Title: YABBY and diverged KNOX1 genes shape nodes and internodes in the stem

Author: Katsutoshi Tsuda, Akiteru Maeno, Ayako Otake, Kae Kato, Wakana Tanaka, Ken-Ichiro Hibara, Ken-Ichi Nonomura

Issue&Volume: 2024-06-14

Abstract: Plant stems comprise nodes and internodes that specialize in solute exchange and elongation. However, their boundaries are not well defined, and how these basic units arise remains elusive. In rice with clear nodes and internodes, we found that one subclade of class I knotted1-like homeobox (KNOX1) genes for shoot meristem indeterminacy restricts node differentiation and allows internode formation by repressing YABBY genes for leaf development and genes from another node-specific KNOX1 subclade. YABBYs promote nodal vascular differentiation and limit stem elongation. YABBY and node-specific KNOX1 genes specify the pulvinus, which further elaborates the nodal structure for gravitropism. Notably, this KNOX1 subclade organization is specific to seed plants. We propose that nodes and internodes are distinct domains specified by YABBY–KNOX1 cross-regulation that diverged in early seed plants.

DOI: adn6748

Source: https://www.science.org/doi/10.1126/science.adn6748