Effect of temperature on wheat streak mosaic disease development in winter wheat

Authors: WOSULA, EVERLYNE - University Of Nebraska; Tatineni, Satyanarayana - Ts; WEGULO, STEPHEN - University Of Nebraska; HEIN, GARY - University Of Nebraska

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/26/2016
Publication Date: 2/1/2017
Publication URL: http://handle.nal.usda.gov/10113/5609495
Citation: Wosula, E.N., Tatineni, S., Wegulo, S., Hein, G.L. 2017. Effect of temperature on wheat streak mosaic disease development in winter wheat. Plant Disease. 101(2):324-330. doi:10.1094/PDIS-07-16-1053-RE.

Interpretive Summary: Information on interaction of a virus with host plants at different temperature regimens is important in predicting disease progression and developing recommendations for effective management. Effect of temperature on Wheat streak mosaic virus (WSMV) in planta movement and disease development was examined using a green fluorescence protein-tagged virus (WSMV-GFP) in resistant (Mace) and susceptible (Tomahawk) winter wheat cultivars. A rapid increase in virus accumulation was observed with increasing temperatures beginning at 15°C in Tomahawk, but this response to temperature was delayed with virus accumulation increasing beginning at 25°C in Mace. In planta WSMV movement at lower temperatures appears to be an important component of infection dynamics in Tomahawk, but this dynamic is significantly altered in Mace. Moreover, some wheat plants that were not systemically infected at 10 and 15°C were found to be infected with the virus in regrowth shoots later at 27°C, suggesting that WSMV moves at undetectable levels under suboptimal temperatures, but rapidly begins to replicate and spread in planta under optimal temperatures. These results indicate that temperature plays an important role in WSMV replication, movement, and disease development in wheat.

Technical Abstract: Temperature is one of the key factors that influence viral disease development in plants. In this study, temperature effect on Wheat streak mosaic virus (WSMV) replication and in planta movement was determined using a green fluorescent protein (GFP)-tagged virus in two winter wheat cultivars. Virus-inoculated plants were first incubated at 10, 15, 20, and 25°C for 21 days, followed by 27°C for 14 days; and, in a second experiment, virus-inoculated plants were initially incubated at 27°C for 3 days, followed by 10, 15, 20, and 25°C for 21 days. In the first experiment, WSMV-GFP in susceptible ‘Tomahawk’ wheat at 10°C was restricted at the point of inoculation whereas, at 15°C, the virus moved systemically, accompanied with mild symptoms, and, at 20 and 25°C, WSMV elicited severe WSMV symptoms. In resistant ‘Mace’ wheat (PI 651043), WSMV-GFP was restricted at the point of inoculation at 10 and 15°C but, at 20 and 25°C, the virus infected systemically with no visual symptoms. Some plants that were not systemically infected at low temperatures expressed WSMV-GFP in regrowth shoots when later held at 27°C. In the second experiment, Tomahawk plants (100%) expressed systemic WSMV-GFP after 21 days at all four temperature levels; however, systemic WSMV expression in Mace was delayed at the lower temperatures. These results indicate that temperature played an important role in WSMV replication, movement, and symptom development in resistant and susceptible wheat cultivars. This study also demonstrates that suboptimal temperatures impair WSMV movement but the virus rapidly begins to replicate and spread in planta under optimal temperatures.