Putative Role of Aquaporins in Variable Hydraulic Conductance of Leaves in Response to Light Export

@article{Cocha07, abstract = {Molecular and physiological studies in walnut (Juglans regia) are combined to establish the putative role of leaf plasma membrane aquaporins in the response of leaf hydraulic conductance (Kleaf) to irradiance. The effects of light and temperature on Kleaf are described. Under dark conditions, Kleaf was low, but increased by 400\% upon exposure to light. In contrast to dark conditions, Kleaf values of light-exposed leaves responded to temperature and 0.1 mM cycloheximide treatments. Furthermore, Kleaf was not related to stomatal aperture. Data of real-time reverse transcription-polymerase chain reaction showed that Kleaf dynamics were tightly correlated with the transcript abundance of two walnut aquaporins (JrPIP2,1 and JrPIP2,2). Low Kleaf in the dark was associated with down-regulation, whereas high Kleaf in the light was associated with up-regulation of JrPIP2. Light responses of Kleaf and aquaporin transcripts were reversible and inhibited by cycloheximide, indicating the importance of de novo protein biosynthesis in this process. Our results indicate that walnut leaves can rapidly change their hydraulic conductance and suggest that these changes can be explained by regulation of plasma membrane aquaporins. Model simulation suggests that variable leaf hydraulic conductance in walnut might enhance leaf gas exchanges while buffering leaf water status in response to ambient light fluctuations. 10.1104/pp.106.090092}, author = {Cochard, Herve and Venisse, Jean-Stephane and Barigah, Tete S. and Brunel, Nicole and Herbette, Stephane and Guilliot, Agnes and Tyree, Melvin T. and Sakr, Soulaiman}, citeulike-article-id = {3857752}, citeulike-linkout-0 = {http://dx.doi.org/10.1104/pp.106.090092}, citeulike-linkout-1 = {http://www.plantphysiol.org/cgi/content/abstract/143/1/122?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&andorexactfulltext=and&searchid=1&FIRSTINDEX=0&sortspec=relevance&volume=143&firstpage=122&resourcetype=HWCIT}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/17114274}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=17114274}, day = {1}, doi = {10.1104/pp.106.090092}, journal = {Plant Physiol.}, keywords = {conductance, interaction, leaf, light-interception}, month = {January}, number = {1}, pages = {122--133}, posted-at = {2009-01-07 17:28:30}, priority = {4}, title = {Putative Role of Aquaporins in Variable Hydraulic Conductance of Leaves in Response to Light}, url = {http://dx.doi.org/10.1104/pp.106.090092}, volume = {143}, year = {2007} }

TY - JOUR ID - Cocha07 L3 - citeulike-article-id:3857752 N2 - Molecular and physiological studies in walnut (Juglans regia) are combined to establish the putative role of leaf plasma membrane aquaporins in the response of leaf hydraulic conductance (Kleaf) to irradiance. The effects of light and temperature on Kleaf are described. Under dark conditions, Kleaf was low, but increased by 400% upon exposure to light. In contrast to dark conditions, Kleaf values of light-exposed leaves responded to temperature and 0.1 mM cycloheximide treatments. Furthermore, Kleaf was not related to stomatal aperture. Data of real-time reverse transcription-polymerase chain reaction showed that Kleaf dynamics were tightly correlated with the transcript abundance of two walnut aquaporins (JrPIP2,1 and JrPIP2,2). Low Kleaf in the dark was associated with down-regulation, whereas high Kleaf in the light was associated with up-regulation of JrPIP2. Light responses of Kleaf and aquaporin transcripts were reversible and inhibited by cycloheximide, indicating the importance of de novo protein biosynthesis in this process. Our results indicate that walnut leaves can rapidly change their hydraulic conductance and suggest that these changes can be explained by regulation of plasma membrane aquaporins. Model simulation suggests that variable leaf hydraulic conductance in walnut might enhance leaf gas exchanges while buffering leaf water status in response to ambient light fluctuations. 10.1104/pp.106.090092 IS - 1 JF - Plant Physiol. EP - 133 TI - Putative Role of Aquaporins in Variable Hydraulic Conductance of Leaves in Response to Light VL - 143 SP - 122 KW - conductance KW - interaction KW - leaf KW - light-interception AU - Cochard, Herve AU - Venisse, Jean-Stephane AU - Barigah, Tete AU - Brunel, Nicole AU - Herbette, Stephane AU - Guilliot, Agnes AU - Tyree, Melvin AU - Sakr, Soulaiman PY - 2007/01/01/ UR - http://dx.doi.org/10.1104/pp.106.090092 ER -