Carbohydrate Stress Affecting Fruitlet Abscission and Expression of Genes Related to Auxin Signal Transduction Pathway in Litchi

International Journal of Molecular Sciences

Jian-Fei Kuang¹  Jian-Yang Wu²  Hai-Ying Zhong¹  Cai-Qin Li²  Jian-Ye Chen¹  Wang-Jin Lu¹ 

[1] State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources/Guangdong Key Laboratory for Postharvest Science, College of Horticulture, South China Agricultural University, Guangzhou 510642, China; E-Mails:;China Litchi Research Center, South China Agricultural University, Guangzhou 510642, China; E-Mails:

关键词: Litchi chinensis Sonn.;    auxin responsive genes;    auxin response factor;    clone;    gene expression;    carbohydrate stress;    fruitlet abscission;   

DOI  :  10.3390/ijms131216084

来源: mdpi

【 摘 要 】

Auxin, a vital plant hormone, regulates a variety of physiological and developmental processes. It is involved in fruit abscission through transcriptional regulation of many auxin-related genes, including early auxin responsive genes (i.e., auxin/indole-3-acetic acid (AUX/IAA), Gretchen Hagen3 (GH3) and small auxin upregulated (SAUR)) and auxin response factors (ARF), which have been well characterized in many plants. In this study, totally five auxin-related genes, including one AUX/IAA (LcAUX/IAA1), one GH3 (LcGH3.1), one SAUR (LcSAUR1) and two ARFs (LcARF1 and LcARF2), were isolated and characterized from litchi fruit. LcAUX/IAA1, LcGH3.1, LcSAUR1, LcARF1 and LcARF2 contain open reading frames (ORFs) encoding polypeptides of 203, 613, 142, 792 and 832 amino acids, respectively, with their corresponding molecular weights of 22.67, 69.20, 11.40, 88.20 and 93.16 kDa. Expression of these genes was investigated under the treatment of girdling plus defoliation which aggravated litchi fruitlet abscission due to the blockage of carbohydrates transport and the reduction of endogenous IAA content. Results showed that transcript levels of LcAUX/IAA1, LcGH3.1 and LcSAUR1 mRNAs were increased after the treatment in abscission zone (AZ) and other tissues, in contrast to the decreasing accumulation of LcARF1 mRNA, suggesting that LcAUX/IAA1, LcSAUR1 and LcARF1 may play more important roles in abscission. Our results provide new insight into the process of fruitlet abscission induced by carbohydrate stress and broaden our understanding of the auxin signal transduction pathway in this process at the molecular level.

【 授权许可】

CC BY   
© 2012 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.