Differential activation of sporamin expression in response to abiotic mechanical wounding and biotic herbivore attack in the sweet potato

BMC Plant Biology

Research Article

Mei-Ju Chen¹  Chien-Yu Chen²  SenthilKumar Rajendran³  Kai-Wun Yeh³  I-Winnie Lin³ 

[1] Genome and Systems Biology Degree Program, National Taiwan University and Academia Sinica, 106, Taipei, Taiwan;Genome and Systems Biology Degree Program, National Taiwan University and Academia Sinica, 106, Taipei, Taiwan;Department of Bio-Industrial Mechatronics Engineering, National Taiwan University, 106, Taipei, Taiwan;Institute of Plant Biology, National Taiwan University, 106, Taipei, Taiwan;

关键词: Sporamin;    Different activation;    Jasmonic acid;    Salicylic acid;    Transcription factors: NAC, WRKY;    ROS;    Transcriptome;    Sweet potato;   

DOI  :  10.1186/1471-2229-14-112

 received in 2013-10-29, accepted in 2014-04-14,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundPlants respond differently to mechanical wounding and herbivore attack, using distinct pathways for defense. The versatile sweet potato sporamin possesses multiple biological functions in response to stress. However, the regulation of sporamin gene expression that is activated upon mechanical damage or herbivore attack has not been well studied.ResultsBiochemical analysis revealed that different patterns of Reactive oxygen species (ROS) and antioxidant mechanism exist between mechanical wounding (MW) and herbivore attack (HA) in the sweet potato leaf. Using LC-ESI-MS (Liquid chromatography electrospray ionization mass spectrometry analysis), only the endogenous JA (jasmonic acid) level was found to increase dramatically after MW in a time-dependent manner, whereas both endogenous JA and SA (salicylic acid) increase in parallel after HA. Through yeast one-hybrid screening, two transcription factors IbNAC1 (no apical meristem (NAM), Arabidopsis transcription activation factor (ATAF), and cup-shaped cotyledon (CUC)) and IbWRKY1 were isolated, which interact with the sporamin promoter fragment of SWRE (sporamin wounding-responsive element) regulatory sequences. Exogenous application of MeJA (methyl jasmonate), SA and DIECA (diethyldithiocarbamic acid, JAs biosynthesis inhibitor) on sweet potato leaves was employed, and the results revealed that IbNAC1 mediated the expression of sporamin through a JA-dependent signaling pathway upon MW, whereas both IbNAC1 and IbWRKY1 coordinately regulated sporamin expression through JA- and SA-dependent pathways upon HA. Transcriptome analysis identified MYC2/4 and JAZ2/TIFY10A (jasmonate ZIM/tify-domain), the repressor and activator of JA and SA signaling among others, as the genes that play an intermediate role in the JA and SA pathways, and these results were further validated by qRT-PCR (quantitative real-time polymerase chain reaction).ConclusionThis work has improved our understanding of the differential regulatory mechanism of sporamin expression. Our study illustrates that sweet potato sporamin expression is differentially induced upon abiotic MW and biotic HA that involves IbNAC1 and IbWRKY1 and is dependent on the JA and SA signaling pathways. Thus, we established a model to address the plant-wounding response upon physical and biotic damage.

【 授权许可】

Unknown   
© Rajendran et al.; licensee BioMed Central Ltd. 2014. 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 credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.