Isbat Mohammad, Zeba Naheed, Kim Seong Ryong, Hong Choo Bong
Department of Life Sciences, Sogang University, Seoul 121-742, Republic of Korea.
J Plant Physiol. 2009 Oct 15;166(15):1685-93. doi: 10.1016/j.jplph.2009.04.017. Epub 2009 Jun 13.
Programmed cell death (PCD) is a highly conserved cellular suicide process important in developmental processes and elimination of damaged cells upon environmental stresses. Among the important regulators of PCD, much interest has been centered on BCL2-associated x protein (BAX) as the pro-PCD factor. On the other hand, BAX inhibitor-1 (BI-1) has been implicated as an anti-PCD factor that balances out the activity of BAX in the developmental processes and responses to environment. A cDNA clone coding a BI-1 gene was isolated from a cDNA library of heat-stressed hot pepper (Capsicum annuum) and named as CaBI-1. This gene contains an open reading frame (ORF) of 248 amino acids encoding a BI-1 protein. Genomic DNA-blot analysis for CaBI-1 suggested one or two loci in the C. annuum genome. Transcription of CaBI-1 was induced in response to high or low temperatures, drought, high salinity, flooding and heavy metal stresses, and ABA. We introduced the ORF of CaBI-1 under the control of the CaMV 35S promoter (P(35S)) into tobacco (Nicotiana tabacum cv. Wisconsin 38) genome by Agrobacterium-mediated transformation. The P(35S):CaBI-1 transgenic plants displayed markedly improved tolerance to high temperature, water deficit, and high salinity in comparison to the control plants. The results indicate that CaBI-1 is a BI-1 gene of which expression induced under various abiotic stresses and endows tolerance to several types of environmental stresses.
程序性细胞死亡（PCD）是一种高度保守的细胞自杀过程，在发育过程以及环境胁迫下受损细胞的清除中起着重要作用。在PCD的重要调节因子中，作为促PCD因子的BCL2相关X蛋白（BAX）备受关注。另一方面，BAX抑制剂-1（BI-1）被认为是一种抗PCD因子，在发育过程和对环境的反应中平衡BAX的活性。从热胁迫的辣椒（Capsicum annuum）cDNA文库中分离出一个编码BI-1基因的cDNA克隆，并将其命名为CaBI-1。该基因包含一个248个氨基酸的开放阅读框（ORF），编码一种BI-1蛋白。对CaBI-1的基因组DNA印迹分析表明，辣椒基因组中有一个或两个位点。CaBI-1的转录在高温或低温、干旱、高盐、水淹和重金属胁迫以及脱落酸（ABA）处理下被诱导。我们通过农杆菌介导的转化将CaMV 35S启动子（P(35S)）控制下的CaBI-1的ORF导入烟草（Nicotiana tabacum cv. Wisconsin 38）基因组。与对照植物相比，P(35S):CaBI-1转基因植物对高温、水分亏缺和高盐的耐受性显著提高。结果表明，CaBI-1是一个在各种非生物胁迫下表达被诱导的BI-1基因，并赋予植物对几种环境胁迫的耐受性。
