%A Honghong Wu, Min Zhu, Lana Shabala, Meixue Zhou and Sergey Shabala %T K+ retention in leaf mesophyll, an overlooked component of salinity tolerance mechanism: A case study for barley %0 Journal Article %D 2015 %J J Integr Plant Biol %R 10.1111/jipb.12238 %P 171-185 %V 57 %N 2 %U {https://www.jipb.net/CN/abstract/article_21384.shtml} %8 2014-07-06 %X

Plant salinity tolerance is a physiologically complex trait, with numerous mechanisms contributing to it. In this work, we show that the ability of leaf mesophyll to retain K+ represents an important and essentially overlooked component of a salinity tolerance mechanism. The strong positive correlation between mesophyll K+ retention ability under saline conditions (quantified by the magnitude of NaCl-induced K+ efflux from mesophyll) and the overall salinity tolerance (relative fresh weight and/or survival or damage under salinity stress) was found while screening 46 barley (Hordeum vulgare L.) genotypes contrasting in their salinity tolerance. Genotypes with intrinsically higher leaf K+ content under control conditions were found to possess better K+ retention ability under salinity and, hence, overall higher tolerance. Contrary to previous reports for barley roots, K+ retention in mesophyll was not associated with an increased H+-pumping in tolerant varieties but instead correlated negatively with this trait. These findings are explained by the fact that increased H+ extrusion may be needed to charge balance the activity and provide the driving force for the high affinity HAK/KUP K+ transporters required to restore cytosolic K+ homeostasis in salt-sensitive genotypes.

 

Wu H, Zhu M, Shabala L, Zhou M, Shabala S (2015) K+ retention in leaf mesophyll, an overlooked component of salinity tolerance mechanism: A case study for barley. J Integr Plant Biol 57: 171–185. doi: 10.1111/jipb.12238