|HOLAPPA LD - WASHINGTON STATE UNIV
|WALKER SIMMONS M - 5348-05-00
Submitted to: Plant Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/4/1995
Publication Date: N/A
Interpretive Summary: Damage to crop plants from drought and extreme cold temperature causes significant losses each growing season. The weather-related damage reduces income to producers and causes unnecessary environmental losses due to the need for replanting. Losses could be reduced if crop plants could acclimate to drought and cold better. Our research has revealed that one of the earliest responses of wheat plants to dehydration and extreme cold is the stimulation of a protein kinase gene. Here, we report that the protein kinase mRNA accumulates within 1 to 2 hours of dehydration or when wheat seedlings are subjected to cold temperature (2degrees C) or high salt conditions. Discovery that the protein kinase gene is induced when wheat seedlings are dried or cold-treated is important because protein kinases are potential regulatory enzymes that can switch on numerous acclimation responses in plants. Next, wheat researchers can determine if there are differences between drought tolerant and intolerant plants in protein kinase regulation. The protein kinase may be a new tool for genetic selection of wheat varieties that can better survive drought or extreme temperatures.
Technical Abstract: The effects of dehydration, cold temperature treatment, and osmotic and salt stress on the exprression of an ABA-responsive protein kinase mRNA (PKABA1) were determined in wheat (Triticum aestivum L.) seedlings. The PKABA1 transcript was detectable at basal levels in tissues of non-stressed plants and accumulated to higher levels in shoot, scutellar, and root tissues of stressed plants. PKABA1 transcript accumulated rapidly (within 2 h) following dehydration and (within 24 h) following other treatments (cold, osmotic stress, and high salt). The rate of accululation of PKABA1 mRNA could not be separated temporally from that of a wheat group 3 LEA mRNA during dehydration and cold treatment. High PKABA1 mRNA levels were measured in field-grown plants growing under cold winter condition, but not under summer, well-watered conditions. These results suggest that PKABA1 may be part of general environmental stress responses in wheat.