Global analysis of basic leucine zipper transcription factors in trifoliate orange and the function identification of PtbZIP49 in salt tolerance  

作　　者：Yuanyuan Xu Qiuling Hui Meng Li Hongxian Peng Yizhong He Changpin Chun Liangzhi Peng Xingzheng Fu 

机构地区：[1]National Citrus Engineering Research Center,Citrus Research Institute,Southwest University,Chongqing 400712,China

出　　处：《Horticultural Plant Journal》2024年第1期115-130,共16页园艺学报（英文版）

基　　金：supported by grants from the National Natural Science Foundation of China(Grant Nos.32072550,31902084);the National Key Research and Development Program of China(Grant No.2018YFD1000300)。

摘　　要：As one of the most widely distributed and highly conserved transcription factors in eukaryotes,basic leucine zipper proteins(bZIPs)are involved in a variety of biological processes in plants,but they are largely unknown in citrus.In this study,56 bZIP family members were identified genome-wide from an important citrus rootstock,namely trifoliate orange(Poncirus trifoliata L.Raf.),and these putative bZIPs were named PtbZIP1—PtbZIP56.All PtbZIPs were classified into 13 subgroups by phylogenetic comparison with Arabidopsis thaliana bZIPs(AtbZIPs),and they were randomly distributed on nine known(50 genes)chromosomes and one unknown(6 genes)chromosome.Sequence analysis revealed the detailed characteristics of PtPZIPs,including their amino acid length,isoelectric point(pI),molecular weight(MW),predicted subcellular localization,gene structure,and conserved motifs.Prediction of promoter elements suggested the presence of drought,low-temperature,wound,and defense and stress responsive elements,as well as multiple hormone-responsive cis-acting elements.Spatiotemporal expression analysis showed the transcriptional patterns of PtbZIPs in different tissues and under dehydration,high salt,ABA,and IAA treatments.In addition,21 PtbZIPs were predicted to have direct or indirect protein—protein interactions.Among these,PtbZIP49 was experimentally proven to interact with PtbZIP1 or PtbZIP11 by using a yeast two-hybrid assay and bimolecular fluorescence complementation(BiFC).Subcellular localization analysis further revealed that PtbZIP1,PtbZIP11,and PtbZIP49 were localized in the nucleus.Moreover,PtbZIP49 was functionally identified as having an important role in salt stress via ectopic expression in A.thaliana and silenced in trifoliate orange using virus-induced gene silencing(VIGS).This study provided comprehensive information on PtbZIP transcription factors in citrus and highlights their potential functions in abiotic stress.

关 键 词：BZIP CITRUS Trifoliate orange Abiotic stress Expression pattern 

分 类 号：S666[农业科学—果树学]