Submitted to: Journal of Plant Interactions
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/10/2018
Publication Date: 12/18/2018
Citation: Barnaby, J.Y., Fleisher, D.H., Sicher Jr, R.C., Reddy, V. 2018. Combined effects of drought and CO2 enrichment on foliar metabolites of potato (Solanum tuberosum L.) cultivars. Journal of Plant Interactions. https://doi.org/10.1080/17429145.2018.1562110.
Interpretive Summary: Climate change predictions indicate that many crop growing regions will experience warmer temperatures and increased episodes of drought. The purpose of this study was to compare a new potato variety, Harley Blackwell, which tolerates high growth temperatures with that of an older, control potato variety. The effects of elevated atmospheric carbon dioxide (CO2) on changes of plant water relations and on various leaf components were examined to understand how these two potato varieties responded to water stress. Our findings confirmed that the new potato variety possessed improved drought tolerance in comparison the older variety and that this was reflected by changes of specific leaf components that respond to drought. These findings should be useful to researchers interested in understanding environmental effects on variety selection and on crop improvement.
Technical Abstract: Increased extreme weather events due to climate change threaten sustainable crop production. Annual variation of drought length and severity impacts potato production, which is sensitive to water stress due to morphological characteristics. Potato varieties respond differently to water stress due to the interactive effects of genotype and environment. Here, we investigate two U.S. Eastern Seaboard potato varieties, [Solanum tuberosum (L) cvs Snowden (full-season) and Harley Blackwell (early maturing, a new variety)], to understand foliar metabolic responses to drought stress and CO2 enrichment (doubled atmospheric CO2 level, 800 ppm, as projected by 2050). Experiments were conducted in outdoor, naturally sunlit, soil-plant-atmosphere research (SPAR) chambers using plants grown in pots. Drought treatment was imposed on potato plants beginning 10 days after tuber initiation. Harley Blackwell, showed enhanced drought tolerance as measured by leaf water potential as compared to Snowden. Among 30 metabolites that differed (p < 0.01) among drought treatments, 16 and 20 were also affected by genotype and by CO2, respectively. Principal component analysis of 30 total drought responsive metabolites showed that phenotypic variation was greater for drought x genotype (PC1, 39.3%) followed by CO2 enrichment (PC2, 15.0%). Most metabolites in Harley Blackwell were lower compared to Snowden. However, phenylalanine, the precursor of lignin biosynthesis, was greater in this newer variety, Harley Blackwell, implying a possible role in cell wall rigidity in the new variety against drought. Current finding provide new and potentially important insights into the mechanisms of drought tolerance in potato.