A Comprehensive Study of the WRKY Transcription Factor Family in Strawberry

Abstract

WRKY transcription factors play critical roles in plant growth and development or stress responses. Using up-to-date genomic data, a total of 64 and 257 WRKY genes have been identified in the diploid woodland strawberry, Fragaria vesca, and the more complex allo-octoploid commercial strawberry, Fragaria × ananassa cv. Camarosa, respectively. The completeness of the new genomes and annotations has enabled us to perform a more detailed evolutionary and functional study of the strawberry WRKY family members, particularly in the case of the cultivated hybrid, in which homoeologous and paralogous FaWRKY genes have been characterized. Analysis of the available expression profiles has revealed that many strawberry WRKY genes show preferential or tissue-specific expression. Furthermore, significant differential expression of several FaWRKY genes has been clearly detected in fruit receptacles and achenes during the ripening process and pathogen challenged, supporting a precise functional role of these strawberry genes in such processes. Further, an extensive analysis of predicted development, stress and hormone-responsive cis-acting elements in the strawberry WRKY family is shown. Our results provide a deeper and more comprehensive knowledge of the WRKY gene family in strawberry.

Genome-wide identification and comprehensive analysis of WRKY transcription factor family in safflower during drought stress

“…Moreover, three types of heptapeptide sequence variations (WKKYGEK, WRKYGKK and WRKYGHK) were found, indicating that the variation in the domain may be one of the reasons for the expansion of WRKY genes in safflower. This phenomenon has been observed in the WRKY members of strawberry, Isatis indigotica, rice, and apple 28 , 32 – 34 . Reportedly, the WRKY domain of GmWRKY6 and GmWRKY21 is a heptapeptide variant sequence WRKYGKK, which has lost the ability to bind to the W-box, affecting the expression pattern of stress-responsive genes of WRKY transcription factor targets 35 .…”

“…In this study, a total of 82 CtWRKY genes were identified from the safflower genome data, which were unevenly distributed on 12 chromosomes (Fig. 2 ) 28 . Furthermore, CtWRKY43 , − 44 , − 45 , and − 46 were grouped together in the identical chromosomal segment, creating a gene cluster, which indicates that these genes might share common biological roles since they are regulated and expressed closely together 5 .…”

“…The WRKY transcription factor family is a plant-specific supergene family that plays a key role in the growth and development of plants as well as biotic and abiotic stresses. Currently, 64, 54, 138, 102, and 125 members of the WRKY gene family have been identified in strawberry, shantung maple, mandarin orange, flax and maize 1 , 4 , 5 , 8 , 28 . In this study, a total of 82 CtWRKY genes were identified from the safflower genome data, which were unevenly distributed on 12 chromosomes (Fig.…”

“…Multiple sequence alignment revealed that most CtWRKY proteins have a highly conserved heptapeptide core sequence (WRKYGQK) and zinc finger structure (C 2 H 2 or C 2 HC) 28 . Moreover, three types of heptapeptide sequence variations (WKKYGEK, WRKYGKK and WRKYGHK) were found, indicating that the variation in the domain may be one of the reasons for the expansion of WRKY genes in safflower.…”

Genome-Wide Analysis of the WRKY Transcription Factor Family in Roses and Their Putative Role in Defence Signalling in the Rose–Blackspot Interaction

“…A more detailed review of WRKY Group I candidates was provided by Jiang et al [ 14 ] for seven Rosaceae species ( Fragaria vesca , Malus domestica , Prunus persica , Pyrus bretschneideri , Prunus mume , and Rubus occidentalis ), which can serve as a basis for further studies. For Prunus mume [ 15 ] and strawberry [ 16 ], more detailed analyses of the entire WRKY family were also carried out. Based on the genome provided by Raymond et al [ 17 ], Liu et al [ 18 ] described 56 candidate WRKYs of Rosa chinensis in more detail and analysed their expression after Botrytis cinerea infection.…”