AUTHOR=Zhang Huijuan , Hong Yongbo , Huang Lei , Liu Shixia , Tian Limei , Dai Yi , Cao Zhongye , Huang Lihong , Li Dayong , Song Fengming 

TITLE=Virus-Induced Gene Silencing-Based Functional Analyses Revealed the Involvement of Several Putative Trehalose-6-Phosphate Synthase/Phosphatase Genes in Disease Resistance against Botrytis cinerea and Pseudomonas syringae pv. tomato DC3000 in Tomato

JOURNAL=Frontiers in Plant Science

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2016.01176

DOI=10.3389/fpls.2016.01176

ISSN=1664-462X

ABSTRACT=<p>Trehalose and its metabolism have been demonstrated to play important roles in control of plant growth, development, and stress responses. However, direct genetic evidence supporting the functions of trehalose and its metabolism in defense response against pathogens is lacking. In the present study, genome-wide characterization of putative trehalose-related genes identified 11 <italic>SlTPSs</italic> for trehalose-6-phosphate synthase, 8 <italic>SlTPPs</italic> for trehalose-6-phosphate phosphatase and one <italic>SlTRE1</italic> for trehalase in tomato genome. Nine <italic>SlTPSs</italic>, 4 <italic>SlTPPs</italic>, and <italic>SlTRE1</italic> were selected for functional analyses to explore their involvement in tomato disease resistance. Some selected <italic>SlTPSs</italic>, <italic>SlTPPs</italic>, and <italic>SlTRE1</italic> responded with distinct expression induction patterns to <italic>Botrytis cinerea</italic> and <italic>Pseudomonas syringae</italic> pv. <italic>tomato</italic> (<italic>Pst</italic>) DC3000 as well as to defense signaling hormones (e.g., salicylic acid, jasmonic acid, and a precursor of ethylene). Virus-induced gene silencing-mediated silencing of <italic>SlTPS3</italic>, <italic>SlTPS4</italic>, or <italic>SlTPS7</italic> led to deregulation of ROS accumulation and attenuated the expression of defense-related genes upon pathogen infection and thus deteriorated the resistance against <italic>B. cinerea</italic> or <italic>Pst</italic> DC3000. By contrast, silencing of <italic>SlTPS5</italic> or <italic>SlTPP2</italic> led to an increased expression of the defense-related genes upon pathogen infection and conferred an increased resistance against <italic>Pst</italic> DC3000. Silencing of <italic>SlTPS3</italic>, <italic>SlTPS4</italic>, <italic>SlTPS5</italic>, <italic>SlTPS7</italic>, or <italic>SlTPP2</italic> affected trehalose level in tomato plants with or without infection of <italic>B. cinerea</italic> or <italic>Pst</italic> DC3000. These results demonstrate that <italic>SlTPS3</italic>, <italic>SlTPS4</italic>, <italic>SlTPS5</italic>, <italic>SlTPS7</italic>, and <italic>SlTPP2</italic> play roles in resistance against <italic>B. cinerea</italic> and <italic>Pst</italic> DC3000, implying the importance of trehalose and tis metabolism in regulation of defense response against pathogens in tomato.</p>