Genome-wide survey of the F-box/Kelch (FBK) members and molecular identification of a novel FBK gene TaAFR in wheat

Abstract

F-box proteins play critical roles in plant responses to biotic/abiotic stresses. In the present study, a total of 68 wheat F-box/Kelch (TaFBK) genes, unevenly distributed across 21 chromosomes and encoding 74 proteins, were identified in EnsemblPlants. Protein sequences were compared with those of Arabidopsis and three cereal species by phylogenetic and domain analyses, where the wheat sequences were resolved into 6 clades. In silico analysis of a digital PCR dataset revealed that TaFBKs were expressed at multiple developmental stages and tissues, and in response to drought and/or heat stresses. The TaFBK19 gene, a homolog of the Attenuated Far-Red Response (AFR) genes in other plant species, and hence named TaAFR, was selected for further analysis. Reverse-transcription quantitative real-time PCR (RT-qPCR) was carried out to determine tissue-specific, hormone and stress (abiotic/biotic) responsive expression patterns. Of interest, TaAFR was expressed most abundantly in the leaves, and its expression in response to leaf rust variants suggests a potential role in compatible vs incompatible rust responses. The protein was predicted to localize in cytosol, but it was shown experimentally to localize in both the cytosol and the nucleus of tobacco. A series of protein interaction studies, starting with a yeast-2-hybrid (Y2H) library screen (wheat leaf infected with incompatible leaf rust pathogens), led to the identification of three TaAFR interacting proteins. Skp1/ASK1-like protein (Skp1) was found to interact with the F-box domain of TaAFR, while ADP-ribosylation factor 2-like isoform X1 (ARL2) and phenylalanine ammonia-lyase (PAL) were shown to interact with its Kelch domain. The data presented herein provides a solid foundation from which the function and metabolic network of TaAFR and other wheat FBKs can be further explored.

Differences in heat tolerance, water use efficiency and growth among Douglas-fir families and varieties evidenced by GWAS and common garden studies

“…From the genes associated with heat stress, we identified PSME_48755 and PSME_04475, F-box/kelch-repeat candidate genes associated with heat tolerance at 35 °C. F-box proteins play critical roles in plant responses to biotic/abiotic stresses and plant developmental process ( Baute et al 2017 ; Wei et al 2021 ). F-box gene transcripts in Arabidopsis highly accumulated in roots and altered their response under drought stress conditions.…”

Transcriptomic Complexity of Culm Growth and Development in Different Types of Moso Bamboo

“…In GRF families, five isoforms obtained F-box-like domain. The F-box domain was commonly found at the N-terminus of various proteins and played a critical role in plant response to various biotic and abiotic stresses via mediating protein–protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression [ 35 ]. Thus, the newly obtained F-box-like domain helped these isoforms improve new functions including plant stress tolerance.…”

Identification of KFB Family in Moso Bamboo Reveals the Potential Function of PeKFB9 Involved in Stress Response and Lignin Polymerization

“…In plants, the KFB subfamily includes members with one to five Kelch repeats consisting of 44–56 residues [ 12 ]. To date, 46, 103, 31, and 36 KFBs have been described in Oryza sativa , Arabidopsis thaliana , Triticum aestivum , and Salvia miltiorrhiza respectively [ 11 , 12 , 13 ].…”

“…In plants, the KFB subfamily includes members with one to five Kelch repeats consisting of 44–56 residues [ 12 ]. To date, 46, 103, 31, and 36 KFBs have been described in Oryza sativa , Arabidopsis thaliana , Triticum aestivum , and Salvia miltiorrhiza respectively [ 11 , 12 , 13 ]. Several KFBs have been characterized and shown to have functions in regulating many important biological processes such as seed germination [ 14 ], hypocotyl elongation [ 15 , 16 ], panicle growth [ 17 ], leaf senescence [ 18 ], and other developmental processes [ 19 , 20 ].…”