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ARS Home » Southeast Area » Dawson, Georgia » National Peanut Research Laboratory » Research » Publications at this Location » Publication #293798
Title: Evaluation of five peanut (Arachis hypogaea L.) genotypes to identify drought responsive mechanisms utilizing candidate-gene approach

Author
item Dang, Phat
item CHEN, CHARLES - Auburn University
item Holbrook, Carl - Corley

Submitted to: Functional Plant Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/5/2013
Publication Date: 9/13/2013
Publication URL: http://DOI: dx.doi.org/10.1071/FP13116
Citation: Dang, P.M., Chen, C., Holbrook Jr, C.C. 2013. Evaluation of five peanut (Arachis hypogaea L.) genotypes to identify drought responsive mechanisms utilizing candidate-gene approach. Functional Plant Biology. 40(12) 1323-1333. https://doi.org/10.1071/FP13116.
DOI: https://doi.org/10.1071/FP13116

Interpretive Summary: Drought can reduce yield and quality in peanut. Because of the variations in levels and severity of drought, plants have evolved complex molecular signaling mechanisms. The precise timing and level of gene-expression for specific genes orchestrate plant drought tolerance or adaptive strategies. The objective of this research was to identify potential molecular mechanism(s) utilizing a candidate-gene approach in five peanut genotypes with contrasting drought responses. An early season drought stress treatment was applied under environmentally controlled rain-out shelters. When water was completely withheld for 3 wks, no physical differences were observed for treated plants compared to their fully irrigated counterparts as indicated by internal leaf moisture measurements. Based on eleven candidate genes and one control gene, three distinct patterns of plant responses were observed. A peanut breeding line, ‘C76-16’, recognized drought stress 1 wk earlier than the others, followed by plant growth ‘adjustment’. Georgia Green, a released cultivar, showed a different pattern of gene-expression than C76-16. AP-3, another cultivar, showed generally lower levels of gene-expression compared to C76-16 and Georgia Green. In general, one or multiple mechanisms of drought response can exist in one plant which can make drought breeding research challenging.

Technical Abstract: Drought can significantly limit yield and quality in peanut (Arachis hypogaea L.), depending the timing, duration or severity. The objective of this research is to identify potential molecular mechanism(s) utilizing a candidate-gene approach in five peanut genotypes with contrasting drought responses. An early season drought stress treatment was applied under environmentally controlled rain-out shelters. When water was completely withheld for 3 wks, no physical differences were observed for treated plants compared to their fully irrigated counterparts as indicated by RWC, but yield, grades (TSMK), SLA, and LDMC showed differences. C76-16 exhibited significantly higher levels of gene-expression 1 wk earlier for CuZnSOD, NsLTP and drought protein, followed by significantly lowest level for the same genes and HSP70 gene-expression level was significantly lower than the other genotypes. This suggested an early recognition of drought in C76-16 and an acclimation response. Georgia Green showed different patterns of gene-expression compared to C76-16. AP-3, a susceptible genotype, showed generally lower levels of gene-expression compared to C76-16 and Georgia Green. Myo-inositol phosphate synthase gene-expression showed high levels in irrigated treatment, ranging from 4 fold for 08T-12 and 12 fold for Georgia Green, but were significantly inhibited in drought treatment after 2 wks of drought and after recovery.