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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #323185
Title: Stress sensitivity is associated with differential accumulation of reactive oxygen and nitrogen species in maize genotypes with contrasting levels of drought tolerance

Author
item YANG, LIMING - University Of Georgia
item FOUNTAIN, JAKE - University Of Georgia
item WANG, HUI - University Of Georgia
item Ni, Xinzhi
item JI, PINGSHENG - University Of Georgia
item LEE, ROBERT - University Of Georgia
item KEMERAIT, ROBERT - University Of Georgia
item Scully, Brian
item Guo, Baozhu

Submitted to: International Journal of Molecular Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/25/2015
Publication Date: 12/20/2015
Citation: Yang, L., Fountain, J., Wang, H., Ni, X., Ji, P., Lee, R.D., Kemerait, R.C., Scully, B.T., Guo, B. 2015. Stress sensitivity is associated with differential accumulation of reactive oxygen and nitrogen species in maize genotypes with contrasting levels of drought tolerance. International Journal of Molecular Sciences. 16:24791-24819. doi: 10.3390/ijms161024791.

Interpretive Summary: Drought stress, with hot and high temperatures during reproductive stage of crop development, can not only reduce crop yield, but also can exacerbate the possibility and severity of Aspergillus flavus infection and aflatoxin contamination in the southern US. Tolerance and adaptation to drought stress is an important trait of crops like maize. However, maize genotypes with contrasting drought tolerances have been shown to possess both common and genotype-specific adaptations to survive the drought stress. In this research, the physiological and metabolic response patterns in the leaves of maize seedlings subjected to drought stress were investigated using six maize genotypes, A638, B73, Grace-E5, Lo964, Lo1016, and Va35. During drought treatments, drought-sensitive maize seedlings displayed more severe symptoms such as chlorosis and wilting, exhibited significant decreases in photosynthetic parameters, and accumulated significantly more reactive oxygen species and reactive nitrogen species than tolerant genotypes. The measured antioxidant enzyme activities were higher in the tolerant genotypes than in the sensitive genotypes in which increased rapidly following drought stress. The results suggest that drought stress causes differential responses to oxidative and nitrosative stress in maize. These differential patterns may be utilized as potential biological markers for use in marker assisted breeding.

Technical Abstract: Drought stress decreases crop growth, yield, and can further exacerbate pre-harvest aflatoxin contamination. Tolerance and adaptation to drought stress is an important trait of agricultural crops like maize. However, maize genotypes with contrasting drought tolerances have been shown to possess both common and genotype-specific adaptations to cope with drought stress. In this research, the physiological and metabolic response patterns in the leaves of maize seedlings subjected to drought stress were investigated using six maize genotypes including: A638, B73, Grace-E5, Lo964, Lo1016, and Va35. During drought treatments, drought-sensitive maize seedlings displayed more severe symptoms such as chlorosis and wilting, exhibited significant decreases in photosynthetic parameters, and accumulated significantly more reactive oxygen species (ROS) and reactive nitrogen species (RNS) than tolerant genotypes. Sensitive genotypes also showed rapid increases in enzyme activities involved in ROS and RNS metabolism. However, the measured antioxidant enzyme activities were higher in the tolerant genotypes than in the sensitive genotypes in which increased rapidly following drought stress. The results suggest that drought stress causes differential responses to oxidative and nitrosative stress in maize genotypes with tolerant genotypes with slower reaction and less ROS and RNS production than sensitive ones. These differential patterns may be utilized as potential biological markers for use in marker assisted breeding.