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ARS Home » Midwest Area » Urbana, Illinois » Global Change and Photosynthesis Research » Research » Publications at this Location » Publication #319036
Title: A comparative analysis of transcriptomic, biochemical and physiological responses to elevated ozone identifies species-specific mechanisms of resilience in legume crops

Author
item YENDREK, C - University Of Illinois
item KOESTER, R - University Of Illinois
item Ainsworth, Elizabeth - Lisa

Submitted to: Journal of Experimental Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/4/2015
Publication Date: 8/31/2015
Citation: Yendrek, C.R., Koester, R.P., Ainsworth, E.A. 2015. A comparative analysis of transcriptomic, biochemical and physiological responses to elevated ozone identifies species-specific mechanisms of resilience in legume crops. Journal of Experimental Botany. doi:10.1093/jxb/erv404.

Interpretive Summary: The concentration of ozone in the lower atmosphere has more than doubled since the industrial revolution and is high enough to damage crop plants. Soybean is sensitive to ozone, and decreases in photosynthesis, growth and yield are observed in soybean exposed to high ozone concentrations. This study investigated the response of soybean and two other legumes-pea and common bean-to elevated ozone concentrations. Three varieties of garden pea were tolerant to ozone, showing no change in photosynthesis, stomatal conductance, or leaf longevity when exposed to elevated ozone concentrations. Common bean, on the other hand, was more sensitive to ozone than soybean. We investigated leaf biochemistry and global transcript abundance and identified that pea had greater apoplastic ascorbate content, foliar glutathione content, and rates of respiration than soybean and common bean. These responses of pea could be used to develop screens for more tolerant varieties soybean and common bean, or used in biotechnology applications to improve their response to elevated ozone.

Technical Abstract: Current concentrations of tropospheric ozone (O3) pollution negatively impact plant metabolism, which can result in decreased crop yields. Interspecific variation in the physiological response of plants to elevated [O3] exists; however, the underlying cellular responses explaining species-specific differences are largely unknown. Here, we performed a physiological screen on multiple varieties of legume species and found that three varieties of garden pea (Pisum sativum L.) were resilient to elevated [O3]. Garden pea showed no change in photosynthetic capacity or leaf longevity when exposed to elevated [O3], in contrast to varieties of soybean (Glycine max (L.) Merr.) and common bean (Phaseolus vulgaris L.). Global transcriptomic and targeted biochemical analyses were then done to examine the mechanistic differences in legume responses to elevated [O3]. In all three species, there was an O3-mediated reduction in specific leaf weight (SLW) and total non-structural carbohydrate (TNC) content, as well as increased abundance of respiration-related transcripts. Differences specific to garden pea included a pronounced increase in the abundance of GLUTATHIONE REDUCTASE transcripts, as well as greater contents of foliar glutathione, apoplastic ascorbate and sucrose in elevated [O3]. These results highlight enhanced capacity of garden pea to detoxify reactive oxygen species (ROS) and thus prevent net losses in CO2 fixation in an elevated [O3] environment.