Cui Songkui, Takeda-Kimura Yuri, Wakatake Takanori, Luo Jun, Tobimatsu Yuki, Yoshida Satoko
Department of Economic Plants and Biotechnology, Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China; State Key Laboratory of Plant Diversity and Prominent Crops, Beijing, China.
Faculty of Agriculture, Yamagata University, Tsuruoka, Yamagata, Japan.
Plant Commun. 2025 May 12;6(5):101294. doi: 10.1016/j.xplc.2025.101294. Epub 2025 Mar 6.
Striga hermonthica, an obligate parasitic plant that causes severe agricultural damage, recognizes its hosts by sensing haustorium-inducing factors (HIFs). Perception of HIFs induces the rapid transformation of S. hermonthica radicles into prehaustoria, structures that enable host invasion and mature into haustoria. HIFs consist of various aromatic compounds, including quinones, lignin monomers, and flavonoids. However, the downstream molecular pathways that orchestrate these developmental events are largely unknown. Here, we report that S. hermonthica root-tip cells rapidly deposit lignin, a major cell wall component, in response to HIFs. In addition to enhancing lignin levels, HIFs strongly induce genes involved in lignin monomer biosynthesis and polymerization, including several respiratory burst oxidase homologs (RBOHs) and class III peroxidases. Disruption of lignin monomer biosynthesis compromises prehaustorium formation, whereas HIF-induced class III peroxidases facilitate the process by promoting lignification. Our study demonstrates that cell wall lignification is a converged cellular process downstream of various HIFs that guides root meristematic cells in prehaustorium development.
独脚金是一种造成严重农业损害的专性寄生植物，它通过感知吸器诱导因子（HIFs）来识别其宿主。对HIFs的感知会诱导独脚金胚根迅速转变为吸器前体，这些结构能够侵入宿主并发育成熟为吸器。HIFs由各种芳香族化合物组成，包括醌类、木质素单体和黄酮类化合物。然而，协调这些发育事件的下游分子途径在很大程度上尚不清楚。在这里，我们报告独脚金根尖细胞会响应HIFs迅速沉积木质素（一种主要的细胞壁成分）。除了提高木质素水平外，HIFs还强烈诱导参与木质素单体生物合成和聚合的基因，包括几种呼吸爆发氧化酶同源物（RBOHs）和Ⅲ类过氧化物酶。木质素单体生物合成的破坏会损害吸器前体的形成，而HIF诱导的Ⅲ类过氧化物酶通过促进木质化作用来推动这一过程。我们的研究表明，细胞壁木质化是各种HIFs下游的一个汇聚细胞过程，它在吸器前体发育过程中引导根分生细胞。
