AUTHOR=Wang Liuqiang , Li Zhen , Lu Mengzhu , Wang Yucheng 

TITLE=ThNAC13, a NAC Transcription Factor from Tamarix hispida, Confers Salt and Osmotic Stress Tolerance to Transgenic Tamarix and Arabidopsis

JOURNAL=Frontiers in Plant Science

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2017.00635

DOI=10.3389/fpls.2017.00635

ISSN=1664-462X

ABSTRACT=<p>NAC (NAM, ATAF1/2, and CUC2) proteins play critical roles in many plant biological processes and environmental stress. However, NAC proteins from <italic>Tamarix hispida</italic> have not been functionally characterized. Here, we studied a <italic>NAC</italic> gene from <italic>T</italic>. <italic>hispida, ThNAC13</italic>, in response to salt and osmotic stresses. ThNAC13 is a nuclear protein with a C-terminal transactivation domain. ThNAC13 can bind to NAC recognized sites and calmodulin-binding NAC (CBNAC) binding element. Overexpression of <italic>ThNAC13</italic> in <italic>Arabidopsis</italic> improved seed germination rate and increased root growth and fresh weight gain under salt or osmotic stress. Transgenic <italic>T</italic>. <italic>hispida</italic> plants transiently overexpressing <italic>ThNAC13</italic> and with RNAi-silenced <italic>ThNAC13</italic> were generated for gain- and loss-of-function experiments. Following exposure to salt or osmotic stress, overexpression of <italic>ThNAC13</italic> induced superoxide dismutase (SOD) and peroxidase (POD) activities, chlorophyll and proline contents; decreased the reactive oxygen species (ROS) and malondialdehyde levels; and reduced electrolyte leakage rates in both transgenic <italic>Tamarix</italic> and <italic>Arabidopsis</italic> plants. In contrast, RNAi-silenced <italic>ThNAC13</italic> showed the opposite results in transgenic <italic>Tamarix</italic>. Furthermore, <italic>ThNAC13</italic> induced the expression of <italic>SOD</italic>s and <italic>POD</italic>s in transgenic <italic>Arabidopsis</italic>. These results suggest that ThNAC13 improves salt and osmotic tolerance by enhancing the ROS-scavenging capability and adjusting osmotic potential.</p>