《植物生理学报》 2016, 52(3): 293-302

拟南芥鸟苷酸环化酶基因AtGC1表达与功能分析

南文斌^*

重庆师范大学生命科学学院, 重庆市植物环境适应分子生物学重点实验室, 重庆401331

通信作者：南文斌；E-mail: nanwenbin513@163.com

摘　要：

第二信使环鸟苷酸(cGMP)在植物生长发育和胁迫应答中具有重要的调节作用, 研究表明cGMP在植物体内由鸟苷酸环化酶(GC)催化合成, 但是目前关于其合成基因GC1 (At5g05930)的表达调控模式和功能仍然知之甚少。因此, 我们构建了pGC1::GUS和p35SGC1::GFP转基因株系, 并对AtGC1基因的表达模式和功能进行了初步探究。结果表明: AtGC1基因在拟南芥各个组织中均有表达, 但根中表达量明显高于其他组织。此外, AtGC1基因的表达能被外源脱落酸(ABA)、生长素(IAA)、赤霉素(GA)和一氧化氮(NO)以及盐和低温胁迫迅速诱导。pGC1::GUS报告基因的结果进一步显示AtGC1基因在拟南芥幼苗主根、侧根、根毛中大量表达, 主根尖分生组织表达量最高。此外, 研究发现虽然超表达株系GC活性显著增加, 但其和基因缺失突变体gc1-1与野生型相比在表型、激素和胁迫响应等方面并未呈现明显差异, 说明GC的编码基因可能具有冗余性, 这些结果为进一步深入研究cGMP信号转导途径提供了证据支持和良好的研究材料。

关键词：cGMP信号; 鸟苷酸环化酶; GC1; 基因表达; 拟南芥

收稿：2015-10-08   修定：2016-01-25

资助：国家自然科学基金(31501190)和重庆市教委科学技术研究项目(KJ1500330)。

The expression and functional study of guanylate cyclase gene AtGC1 in Arabidopsis

NAN Wen-Bin^*

Chongqing Key Laboratory of Molecular Biology of Plants Environmental Adaptations, College of Life Sciences, Chongqing Normal University, Chongqing 401331, China

Corresponding author: NAN Wen-Bin; E-mail: nanwenbin513@163.com

Abstract:

The second messenger cyclic guanosine 3’, 5’-monophosphate (cGMP) plays an important role in plant development and responses to stresses. Studies indicated that the generation of cGMP in plant is catalyzed by guanylate cyclase (GC), and the encoding gene GC1 (At5g05930) of GC was identified in Arabidopsis. Nonetheless, the expression pattern and mechanism of GC1 participation in cGMP signal to affect plant growth and developmental is largely unknown. Therefore, in this study, the transgenic lines pGC1::GUS and p35SGC1::GFP were constructed, and the expression pattern and function of GC1 gene were studied in Arabidopsis. Results showed that the expression of GC1 gene was detected in all tissues of Arabidopsis, while was obviously higher in root than other tissues. It can be rapidly induced by exogenous ABA, IAA, GA and NO, as well as salt and low temperature stresses. The results of pGC1::GUS reporter gene further showed that the GC1 gene mainly expresses in primary root, lateral root and root hair of Arabidopsis seedlings. The highest expression was found in meristem tissue of primary root tips. In addition, the analysis of GC1 over-expression plants showed that the GC activity increases markedly. However, the over-expression line GC1-OE 12# and gc1-1 mutant did not produce any different effects for phenotype, hormone and stress responses compared to controls, suggested that the encoding genes of GC are redundant. These results provided the evidence and good study materials for further indepth research on cGMP signal transduction pathways.

Key words: cGMP signal; guanylate cyclase; GC1; gene expression; Arabidopsis