AUTHOR=Nan Hong , Gao Li-zhi 

TITLE=Genome-Wide Analysis of WRKY Genes and Their Response to Hormone and Mechanic Stresses in Carrot

JOURNAL=Frontiers in Genetics

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2019.00363

DOI=10.3389/fgene.2019.00363

ISSN=1664-8021

ABSTRACT=<p>The <italic>WRKY</italic> gene family plays a vital role in plant development and environment response. Although previous studies suggested that the <italic>WRKY</italic> genes in carrot (Kuroda type) involved in biotic and abiotic stress responses, the information of <italic>WRKY</italic> genes in the latest version of the carrot genome (<italic>Daucus carota</italic> v2.0, Nantes type carrot) and their response to hormone and injury stresses have not been reported. In this study, we performed a genome-wide analysis of <italic>WRKY</italic>s using a chromosome-scale genome assembly of carrot (<italic>Daucus carota</italic> subsp. <italic>sativus</italic> L.). We identified a total of 67 <italic>WRKY</italic> genes, which were further classified into the three groups. These <italic>WRKY</italic> genes are unevenly distributed on carrot chromosomes. We found that more than half of them were derived from whole-genome duplication (WGD) events, suggesting that WGDs have played a major role during the evolution of the <italic>WRKY</italic> gene family. We experimentally ascertained the expression divergence existed between WGD-derived <italic>WRKY</italic> duplicated gene pairs, which is indicative of functional differentiation between duplicated genes. Our analysis of <italic>cis</italic>-acting elements indicated that <italic>WRKY</italic> genes were transcriptionally regulated upon hormone and mechanic injury stresses. Gene expression analyses by qRT-PCR further presented that <italic>WRKY</italic> genes were involved in hormone and mechanic injury stresses.</p>