Screening of a Peanut (Arachis hypogaea L.) cDNA Library To Isolate a Bowman-Birk Trypsin Inhibitor Clone

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• 作者：Judith A. Boateng ; Olga M. Viquez ; Koffi N. Konan ; and Hortense W. Dodo
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2005
• 出版时间：March 23, 2005
• 年：2005
• 卷：53
• 期：6
• 页码：2028 - 2031
• 全文大小：254K
• 年卷期：v.53,no.6(March 23, 2005)
• ISSN：1520-5118

文摘

Peanut crop losses due to insect and pest infestation cost peanut farmers nearly 20% of their annualyields. The conventional use of chemicals to combat this problem is costly and toxic to humans andlivestock and leads to the development of resistance by target insects. Transgenic plants expressinga trypsin inhibitor gene in tobacco and cowpea have proven to be efficient for resistance againstinsects. Therefore, a transgenic peanut overexpressing a trypsin inhibitor gene could be an alternativesolution to the use of toxic chemicals. Five Bowman-Birk trypsin inhibitor (BBTI) proteins werepreviously isolated from peanut. However, to date, neither cDNA nor genomic DNA sequences areavailable. The objective of this research was to screen a peanut cDNA library to isolate and sequenceat least one full-length peanut BBTI cDNA clone. Two heterologous oligonucleotides were constructedon the basis of a garden pea (Pisum sativa) trypsin inhibitor nucleotide sequence and used as probesto screen a peanut lambda gt-11 cDNA library. Two positive and identical cDNA clones were isolated,subcloned into a pBluescript vector, and sequenced. Sequence analysis revealed a full-length BBTIcDNA of about 243 bp, with a start codon ATG at position +1 and a stop codon TGA at position+243. In the 3' end, two poly adenylation signals (AATAAA) were identified at positions +261 and+269. The isolated cDNA clone encodes a protein of 80 amino acid residues including a leadersequence of 11 amino acids. The deduced amino acid sequence is 100% identical to publishedsequences of peanut BBTI AI, AII, BI, and BIII and 81% identical to BII.Keywords: Peanut; Bowman-Birk trypsin inhibitor; insects; transgenics; cDNA library; heterologousprobes; plant defense