AUTHOR=Saand Mumtaz A. , Xu You-Ping , Li Wen , Wang Ji-Peng , Cai Xin-Zhong 

TITLE=Cyclic nucleotide gated channel gene family in tomato: genome-wide identification and functional analyses in disease resistance

JOURNAL=Frontiers in Plant Science

VOLUME=6

YEAR=2015

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2015.00303

DOI=10.3389/fpls.2015.00303

ISSN=1664-462X

ABSTRACT=<p>The cyclic nucleotide gated channel (CNGC) is suggested to be one of the important calcium conducting channels. Nevertheless, genome-wide identification and systemic functional analysis of <italic>CNGC</italic> gene family in crop plant species have not yet been conducted. In this study, we performed genome-wide identification of <italic>CNGC</italic> gene family in the economically important crop tomato (<italic>Solanum lycopersicum</italic> L.) and analyzed function of the group IVb <italic>SlCNGC</italic> genes in disease resistance. Eighteen <italic>CNGC</italic> genes were identified in tomato genome, and four <italic>CNGC</italic> loci that were misannotated at database were corrected by cloning and sequencing. Detailed bioinformatics analyses on gene structure, domain composition and phylogenetic relationship of the <italic>SlCNGC</italic> gene family were conducted and the group-specific feature was revealed. Comprehensive expression analyses demonstrated that <italic>SlCNGC</italic> genes were highly, widely but differently responsive to diverse stimuli. Pharmacological assays showed that the putative CNGC activators cGMP and cAMP enhanced resistance against <italic>Sclerotinia sclerotiorum</italic>. Silencing of group IVb <italic>SlCNGC</italic> genes significantly enhanced resistance to fungal pathogens <italic>Pythium aphanidermatum</italic> and <italic>S. sclerotiorum</italic>, strongly reduced resistance to viral pathogen <italic>Tobacco rattle virus</italic>, while attenuated PAMP- and DAMP-triggered immunity as shown by obvious decrease of the flg22- and AtPep1-elicited hydrogen peroxide accumulation in <italic>SlCNGC</italic>-silenced plants. Additionally, silencing of these <italic>SlCNGC</italic> genes significantly altered expression of a set of Ca<sup>2+</sup> signaling genes including <italic>SlCaMs</italic>, <italic>SlCDPKs,</italic> and <italic>SlCAMTA3</italic>. Collectively, our results reveal that group IV <italic>SlCNGC</italic> genes regulate a wide range of resistance in tomato probably by affecting Ca<sup>2+</sup> signaling.</p>