AUTHOR=Li Xiaohui , Zhang Huijuan , Tian Limei , Huang Lei , Liu Shixia , Li Dayong , Song Fengming 

TITLE=Tomato SlRbohB, a member of the NADPH oxidase family, is required for disease resistance against Botrytis cinerea and tolerance to drought stress

JOURNAL=Frontiers in Plant Science

VOLUME=6

YEAR=2015

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2015.00463

DOI=10.3389/fpls.2015.00463

ISSN=1664-462X

ABSTRACT=<p>NADPH oxidases (also known as respiratory burst oxidase homologs, Rbohs) are key enzymes that catalyze the generation of reactive oxygen species (ROS) in plants. In the present study, eight <italic>SlRboh</italic> genes were identified in tomato and their possible involvement in resistance to <italic>Botrytis cinerea</italic> and drought tolerance was examined. Expression of <italic>SlRbohs</italic> was induced by <italic>B. cinerea</italic> and <italic>Pseudomonas syringae</italic> pv. <italic>tomato</italic> but displayed distinct patterns. Virus-induced gene silencing based silencing of <italic>SlRbohB</italic> resulted in reduced resistance to <italic>B. cinerea</italic> but silencing of other <italic>SlRbohs</italic> did not affect the resistance. Compared to non-silenced plants, the <italic>SlRbohB</italic>-silenced plants accumulated more ROS and displayed attenuated expression of defense genes after infection with <italic>B. cinerea</italic>. Silencing of <italic>SlRbohB</italic> also suppressed flg22-induced ROS burst and the expression of <italic>SlLrr22</italic>, a marker gene related to PAMP-triggered immunity (PTI). Transient expression of <italic>SlRbohB</italic> in <italic>Nicotiana benthamiana</italic> led to enhanced resistance to <italic>B. cinerea</italic>. Furthermore, silencing of <italic>SlRbohB</italic> resulted in decreased drought tolerance, accelerated water loss in leaves and the altered expression of drought-responsive genes. Our data demonstrate that SlRbohB positively regulates the resistance to <italic>B. cinerea</italic>, flg22-induced PTI, and drought tolerance in tomato.</p>