Submitted to: Peanut Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 1, 2001
Publication Date: August 28, 2001
Citation: Xue, G., Guo, B., Holbrook, Jr., C.C., Lynch, R.E. 2001. Identification and partial sequence of a PLD-like gene encoding for phospholipase D in peanut. Peanut Science and Technology. 30(4):1-10. Interpretive Summary: The production of quality peanuts is the number one goal of the U.S. peanut industry since the majority of peanuts produced in the U.S. are for human consumption. The most serious challenge to quality peanuts is preharvest contamination with aflatoxin, a potent cancer-producing toxin produced by the fungus Aspergillus flavus. Aflatoxin contamination occurs when peanuts sgrowing in the field are exposed to severe drought during the latter part of the growing season. The development of peanut lines with resistance to drought stress would represent a major advance for the peanut industry. Our research goal is to identify factors associated with resistance to aflatoxin, drought stress or insects and to develop markers to assist in the transfer of the resistance to commercial peanut lines. We have identified a novel gene that may well be associated with drought tolerance in peanut. It is the first such gene identified in peanut and has characteristics similar to those identified in other crops for drought resistance. Additional study is needed, however, to characterize the gene and to develop markers for this gene.
Technical Abstract: Preharvest aflatoxin contamination has been identified by the peanut industry as the most serious challenge facing the industry worldwide. Drought stress is the most important environmental factor exacerbating Aspergillus infection and aflatoxin contamination in peanut. Development of resistant peanut cultivars would represent a major advance for the U.S. peanut industry. In this study, we identify a novel PLD-like gene, encoding a putative phospholipase D, a main enzyme responsible for the drought-induced degradation of membrane phospholipids in plants. This cloned PLD1 fragment has 1069 bp nucleic acids and the deduced amino acid sequence shows high identity with known PLD genes, having similar conserved features, such as two KXKXXXXD motifs. Further study is needed to genetically and physiologically characterize the PLD in peanut and to gain a better understanding of its function and relationship with drought- tolerance.