Submitted to: Journal of Plant Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 6, 2012
Publication Date: June 15, 2012
Citation: Dombrowski, J.E., Martin, R.C. 2012. Abiotic stresses activate a MAPkinase in the model grass species Lolium temulentum L. Journal of Plant Physiology. 169: 915-919. Interpretive Summary: Forage and turf grasses are utilized in diverse environments, which exposes them to a variety of abiotic stresses, however very little is known concerning the perception or molecular responses to these various stresses. This research discovered that a key protein that acts as a conduit for signals perceived by the plant is rapidly activated when forage and turf grasses are exposed to different abiotic stresses. This class of protein is an important signaling protein that mediates the plants response to these various stresses. This research provides an important the first step towards elucidating the molecular mechanisms utilized by grasses in response environmental stresses and how they are perceived. In the long term this information can lead to improvements and increases in the yield, sustainability and the quality of grasses used as a feedstock for livestock and biofuels in different end-use environments.
Technical Abstract: Forage and turf grasses are utilized in diverse environments which exposes them to a variety of abiotic stresses, however very little is known concerning the perception or molecular responses to these various stresses. In the model grass species Lolium temulentum (Lt), a 46 kDa mitogen-activated protein kinase (MAPK) in the leaf was activated within 10 minutes of exposing the roots to 200 mM NaCl salt stress. When plants were subjected to 4 °C and 0 °C cold stress, no significant activation of the MAPK was observed. However, the 46 kDa MAPK was rapidly activated in the leaves of plants within 3 minutes of exposure to either 30 °C or 40 °C heat stress. Previously it has been shown that mechanical wounding rapidly activated a 46 kDa and a 44 kDa MAPK in Lt. The wound activation of the MAPKs was delayed and diminished in plants under-going cold treatment at 4 °C and 0 °C. In plants subjected simultaneously to 40 °C and wounding, the activation of the 46 kDa MAPK was enhanced. However if plants were subjected to heat stress for more than 1-2 hours prior to wounding, the wound activation of the 46 kDa and a 44 kDa MAPKs was significantly inhibited. These results suggest that the 46 kDa MAPK plays a role in the response to various environmental stimuli.