AUTHOR=Yang Ying , Wang Jiayan , Xu Yan , Abbas Farhat , Xu Dongbin , Tao Shenchen , Xie Xiaoting , Song Feng , Huang Qiaoyu , Sharma Anket , Zheng Luqing , Yan Daoliang , Wang Xiaofei , Zheng Bingsong , Yuan Huwei , Wu Rongling , He Yi 

TITLE=Genome-wide identification and expression analysis of AUX/LAX family genes in Chinese hickory (Carya cathayensis Sarg.) Under various abiotic stresses and grafting

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.1060965

DOI=10.3389/fpls.2022.1060965

ISSN=1664-462X

ABSTRACT=<p>Auxin is essential for regulating plant growth and development as well as the response of plants to abiotic stresses. AUX/LAX proteins are auxin influx transporters belonging to the amino acid permease family of proton-driven transporters, and are involved in the transport of indole-3-acetic acid (IAA). However, how <italic>AUX/LAX</italic> genes respond to abiotic stresses in Chinese hickory is less studied. For the first time identification, structural characteristics as well as gene expression analysis of the <italic>AUX/LAX</italic> gene family in Chinese hickory were conducted by using techniques of gene cloning and real-time fluorescent quantitative PCR. Eight <italic>CcAUX/LAXs</italic> were identified in Chinese hickory, all of which had the conserved structural characteristics of <italic>AUX/LAXs</italic>. CcAUX/LAXs were most closely related to their homologous proteins in <italic>Populus trichocarpa</italic> , which was in consistence with their common taxonomic character of woody trees. <italic>CcAUX/LAXs</italic> exhibited different expression profiles in different tissues, indicating their varying roles during growth and development. A number of light-, hormone-, and abiotic stress responsive <italic>cis</italic>-acting regulatory elements were detected on the promoters of <italic>CcAUX/LAX</italic> genes. <italic>CcAUX/LAX</italic> genes responded differently to drought and salt stress treatments to varying degrees. Furthermore, <italic>CcAUX/LAX</italic> genes exhibited complex expression changes during Chinese hickory grafting. These findings not only provide a valuable resource for further functional validation of <italic>CcAUX/LAXs</italic>, but also contribute to a better understanding of their potential regulatory functions during grafting and abiotic stress treatments in Chinese hickory.</p>