A BAX inhibitor-1 gene in Capsicum annuum is induced under various abiotic stresses and endows multi-tolerance in transgenic tobacco.
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.
Isbat
Mohammad
M
Department of Life Sciences, Sogang University, Seoul 121-742, Republic of Korea.
Zeba
Naheed
N
Kim
Seong Ryong
SR
Hong
Choo Bong
CB
D000595:Amino Acid Sequence; D001483:Base Sequence; D002212:Capsicum / Q000235:genetics* / Q000502:physiology; D003890:Desiccation; D015723:Gene Library; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D030821:Plants, Genetically Modified / Q000033:anatomy & histology / Q000254:growth & development / Q000502:physiology*; D016415:Sequence Alignment; D012965:Sodium Chloride / Q000378:metabolism; D013312:Stress, Physiological / Q000235:genetics*; D013696:Temperature; D014026:Nicotiana / Q000033:anatomy & histology / Q000235:genetics* / Q000502:physiology
D010940:Plant Proteins; D012965:Sodium Chloride