《植物生理学报》 2013, 49(5): 485-492

复制因子C亚基3基因(RFC3)突变降低了拟南芥植株复制损伤的修复能力

陈良城, 陈锦, 崔看, 李依驰, 萧浪涛, 夏石头^*

湖南农业大学生物科学技术学院, 植物激素与生长发育湖南省重点实验室, 长沙410128

通信作者：夏石头；E-mail: xstone0505@hunau.net；Tel: 0731-84635260

摘　要：

以拟南芥rfc3-1突变体为材料, 研究了复制因子C亚基3基因(RFC3)突变对植株抗不同浓度DNA复制毒性物质甲基磺酸甲酯(MMS)和顺铂(cisplatin)的影响。结果表明, rfc3-1、野生型和rfc3-1/RFC3植株生长受抑制程度随MMS和cisplatin浓度上升而增加, rfc3-1植株主根长度和真叶数极显著或显著小于野生型和rfc3-1/RFC3植株的, 遗传互补植株rfc3-1/RFC3则恢复了rfc3-1的野生型表型。荧光定量PCR分析显示, 在140 mg·L-1 MMS或40 μmol·L-1 cisplatin处理下, 与野生型与rfc3-1/RFC3植株相比, rfc3-1植株中GR1、KU70、MRE11、RAD51和BRCA1的表达量大幅度上调, 而rfc3-1的初电导率和相对电导率都显著高于野生型和rfc3-1/RFC3的, 说明RFC3基因突变削弱了植株对MMS和cisplatin的抗性, AtRFC3对植株抗DNA 复制损伤修复和抗性生长具有重要调控作用。

关键词：AtRFC3; DNA复制; 损伤修复; 电导率

收稿：2013-03-01   修定：2013-04-22

资助：资助 国家自然科学基金项目(30970247)、湖南省自然科学杰出青年基金项目(11JJ1007)和作物种质创新与资源利用国家重点实验室培育基地开放重点项目。 * 通讯作者

Mutation in Replication Factor C Subunit 3 Compromises Plant Repair Capa-bility to Replication Damage in Arabidopsis thaliana

CHEN Liang-Cheng, CHEN Jin, CUI Kan, LI Yi-Chi, XIAO Lang-Tao, XIA Shi-Tou*

Hunan Provincial Key Laboratory of Phytohormones and Growth Development, College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China

Corresponding author: XIA Shi-Tou; E-mail: xstone0505@hunau.net; Tel: 0731-84635260

Abstract:

The effects of mutation in replication factor C subunit 3 gene (RFC3) on the resistance to toxicant methyl methanesulfonate (MMS) and cisplatin of different concentrations were studied using rfc3-1 mutant as material in the paper. The results showed that the suppressive effect on plant growth of rfc3-1, wild type (WT) and rfc3-1/RFC3 increased with the concentration of MMS and cisplatin. However, the length of the main roots and the number of true leaves of rfc3-1 plant were found to be significantly smaller than those of WT and rfc3-1/RFC3 plants at 0.01 or 0.05 level, and the complementary plant rfc3-1/RFC3 rescued the mutated phenotype of rfc3-1. Real-time PCR analyses showed that comparing with the WT and rfc3-1/RFC3 plants, the expression of GR1 (gamma response 1), KU70 (Lupus Ku autoantigen protein p70), MRE11 (meiotic recombination 11), RAD51 (radiation sensitivity gene 51) and BRCA1 (BREAST CANCER SUSCEPTIBILITY 1) was massively up-regulated with the treatment of 140 mg·L-1 MMS or 40 μmol·L-1 cisplatin, and the primary as well as relative conductivities in rfc3-1 plant were significantly higher than those in the WT and rfc3-1/RFC3 plants. It is suggested that mutation in RFC3 compromises the resistance to DNA toxicant MMS and cisplatin, and AtRFC3 plays an important regulatory role in replication damage repair in Arabidopsis thaliana.

Key words: AtRFC3; DNA replication; damage repair; conductivity