Abstract
Drought and high salinity are two major abiotic stresses that significantly affect agricultural crop productivity worldwide. Annexins are a multigene family that plays an essential role in plant stress responses and various cellular processes. Here, the AnnSp2 gene was cloned from drought-resistant wild tomato (Solanum pennellii) and functionally characterized in cultivated tomato. AnnSp2 protein was localized in the nucleus and had higher expression in leave, flower and fruit. It was induced by several phytohormones and some abiotic stresses. Tomato plants overexpressing AnnSp2 had increased tolerance to drought and salt stress, as determined by analysis of various physiological parameters. AnnSp2-transgenic plants were less sensitive to ABA during the seed germination and seedling stages. However, under drought stress, the ABA content significantly increased in the AnnSp2-overexpressing plants, inducing stomatal closure and reducing water loss, which underlay the plants’ enhanced stress tolerance. Furthermore, scavenging reactive oxygen species (ROS), higher total chlorophyll content, lower lipid peroxidation levels, increased peroxidase activities (including APX, CAT and SOD) and higher levels of proline were observed in AnnSp2-overexpressing plants. These results indicate that overexpression of AnnSp2 in transgenic tomato improves salt and drought tolerance through ABA synthesis and the elimination of ROS.
Highlights
Some subsequent reports focused on the roles of plant annexins involved in stress signaling[7,8,9]
A blast homology search of the tomato genome database showed that the AnnSp2 gene was located in chromosome 4
We previously reported that AnnSp2 is associated with the stress-responsive protein SpUSP35
Summary
Some subsequent reports focused on the roles of plant annexins involved in stress signaling[7,8,9]. The phytohormone ABA plays a key role in regulating a range of plant physiological processes in response to various stresses[18,19,20,21] Osmotic stress, such as drought and high salinity, dramatically increases the ABA level, which in turn induces the expression of many genes involved in stress responses[22,23,24]. Our results demonstrate that AnnSp2 enhances tolerance to high salinity and oxidative stress by regulating the expression of stress related genes These data provide new insight into the mechanism by which annexin proteins function in ABA synthesis, which may lead to targeted genetic manipulation of crop plants to improve stress tolerance
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
