AUTHOR=Yang Chuyun , Xie Zhuomi , Qian Sheng , Zhang Junyi , Yu Zhijian , Li Mingjie , Gu Li , Qin Shuangshuang , Zhang Zhongyi 

TITLE=Functional analysis of Rehmannia glutinosa key LRR-RLKs during interaction of root exudates with Fusarium oxysporum reveals the roles of immune proteins in formation of replant disease

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.1044070

DOI=10.3389/fpls.2022.1044070

ISSN=1664-462X

ABSTRACT=<p>Previous studies have indicated that some <italic>Rehmannia glutinosa</italic> Leucine-rich repeat receptor-like protein kinases (LRR-RLKs) are involved in the formation of replant disease. However, it remains unclear how the interaction of LRR-RLKs with a key factor, the interaction between root exudates and <italic>Fusarium oxysporum</italic>, results in formation of replant disease. In this study, the influences of root exudates, <italic>F. oxysporum</italic> and the interaction of these two factors on expression of nine <italic>R. glutinosa LRR-RLKs</italic> (<italic>RgLRRs</italic>) were analyzed. The resulting eight <italic>RgLRRs</italic> of them were highly expressed at the early stage, and rapidly declined at later stages under mixed treatment of root exudates and <italic>F. oxysporum</italic>. The functions of nine <italic>RgLRRs</italic> under root exudates, <italic>F. oxysporum</italic> and mixed treatment of root exudates and <italic>F. oxysporum</italic> were preliminarily analyzed using transient overexpression and RNAi experiments. The results showed that high expression of <italic>RgLRR19</italic>, <italic>RgLRR21</italic>, <italic>RgLRR23</italic> and <italic>RgLRR29</italic> could decrease the damage to root cells from the mixed treatment of root exudates and <italic>F. oxysporum</italic>, but the interference of these genes enhanced the damage levels of root cells. Based on this, stable transgenic <italic>R. glutinosa</italic> seedlings were acquired. Overexpression of <italic>RgLRR29</italic> conferred resistance of <italic>R. glutinosa</italic> seedlings to root exudates, <italic>F. oxysporum</italic> and mixed treatment. These results indicated that the continuous proliferation of <italic>F. oxysporum</italic> supported by root exudates altered the expression patterns of <italic>RgLRRs</italic> in <italic>R. glutinosa</italic>, then disordered the growth and development of <italic>R. glutinosa</italic>, finally leading to the formation of replant disease.</p>