Genome-wide analysis of the GH3 family in apple (Malus × domestica)

BMC Genomics

Research Article

Tianhong Li¹  Xinjie Shen¹  Huazhao Yuan¹  Hengjiu Lei¹  Xiong Liao¹  Kai Zhao¹  Yun Liu¹ 

[1] Department of Fruit Science, College of Agriculture and Biotechnology/Key Laboratory of Stress Physiology and Molecular Biology for Tree Fruits of Beijing, China Agricultural University, 2 Yuanmingyuan West Road, Haidian District, 100193, Beijing, People’s Republic of China;

关键词: Malus sieversii;    Phytohormone;    Biotic stress;    GH3;    DR5;    GUS;   

DOI  :  10.1186/1471-2164-14-297

 received in 2013-03-21, accepted in 2013-04-25,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundAuxin plays important roles in hormone crosstalk and the plant’s stress response. The auxin-responsive Gretchen Hagen3 (GH3) gene family maintains hormonal homeostasis by conjugating excess indole-3-acetic acid (IAA), salicylic acid (SA), and jasmonic acids (JAs) to amino acids during hormone- and stress-related signaling pathways. With the sequencing of the apple (Malus × domestica) genome completed, it is possible to carry out genomic studies on GH3 genes to indentify candidates with roles in abiotic/biotic stress responses.ResultsMalus sieversii Roem., an apple rootstock with strong drought tolerance and the ancestral species of cultivated apple species, was used as the experimental material. Following genome-wide computational and experimental identification of MdGH3 genes, we showed that MdGH3s were differentially expressed in the leaves and roots of M. sieversii and that some of these genes were significantly induced after various phytohormone and abiotic stress treatments. Given the role of GH3 in the negative feedback regulation of free IAA concentration, we examined whether phytohormones and abiotic stresses could alter the endogenous auxin level. By analyzing the GUS activity of DR5::GUS-transformed Arabidopsis seedlings, we showed that ABA, SA, salt, and cold treatments suppressed the auxin response. These findings suggest that other phytohormones and abiotic stress factors might alter endogenous auxin levels.ConclusionPrevious studies showed that GH3 genes regulate hormonal homeostasis. Our study indicated that some GH3 genes were significantly induced in M. sieversii after various phytohormone and abiotic stress treatments, and that ABA, SA, salt, and cold treatments reduce the endogenous level of axuin. Taken together, this study provides evidence that GH3 genes play important roles in the crosstalk between auxin, other phytohormones, and the abiotic stress response by maintaining auxin homeostasis.

【 授权许可】

Unknown   
© Yuan et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.