Lu Songmao, Deng Huobing, Lin Yaqi, Huang Meimei, You Haixia, Zhang Yan, Zhuang Weijian, Lu Guodong, Yun Yingzi
State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350001, China.
Fujian Institute of Tropical Crops, Zhangzhou 363001, China.
J Fungi (Basel). 2023 Dec 19;10(1):1. doi: 10.3390/jof10010001.
The conidia produced by f. sp. (Foc), the causative agent of Fusarium Wilt of Banana (FWB), play central roles in the disease cycle, as the pathogen lacks a sexual reproduction process. Until now, the molecular regulation network of asexual sporogenesis has not been clearly understood in Foc. Herein, we identified and functionally characterized thirteen (13) putative sporulation-responsive genes in Foc, namely , , , , , , , , , , , and . We demonstrated that , , , , , , and mediate conidiophore formation, whereas and are important for phialide formation and conidiophore formation. The expression level of was significantly decreased in the Δ mutant, and yeast one-hybrid and ChIP-qPCR analyses further confirmed that FocMedA(a) could bind to the promoter of during micro- and macroconidiation. Moreover, the transcript abundance of the gene was significantly reduced in the Δ mutant, and it not only was found to function as an activator of micro- and macroconidium formation but also served as a repressor of chlamydospore production. In addition, the deletions of , , and resulted in increased chlamydosporulation, whereas and gene deletions reduced chlamydosporulation. Furthermore, , , and were found to be important regulators for pathogenicity and fusaric acid synthesis in Foc. The present study therefore advances our understanding of the regulation pathways of the asexual development and functional interdependence of sporulation-responsive genes in Foc.
香蕉枯萎病菌（Foc）的专化型产生的分生孢子在病害循环中起核心作用，因为该病原菌缺乏有性生殖过程。到目前为止，Foc中无性孢子形成的分子调控网络尚未被清楚了解。在此，我们鉴定并对Foc中的13个假定的孢子形成响应基因进行了功能表征，即 、 、 、 、 、 、 、 、 、 、 、 和 。我们证明 、 、 、 、 、 、 和 介导分生孢子梗形成，而 和 对产孢瓶梗形成和分生孢子梗形成很重要。在Δ 突变体中， 的表达水平显著降低，酵母单杂交和ChIP-qPCR分析进一步证实，在微分生孢子和大分生孢子形成过程中，FocMedA(a)可与 的启动子结合。此外，在Δ 突变体中， 基因的转录丰度显著降低，它不仅被发现作为微分生孢子和大分生孢子形成的激活因子，还作为厚垣孢子产生的抑制因子。此外， 、 、 和 的缺失导致厚垣孢子形成增加，而 和 基因缺失减少了厚垣孢子形成。此外，发现 、 、 和 是Foc中致病性和镰刀酸合成的重要调节因子。因此，本研究增进了我们对Foc中无性发育调控途径以及孢子形成响应基因功能相互依赖性的理解。
