AUTHOR=Zhang Huai-Xia , Zhang Yuan , Zhang Bo-Wen 

TITLE=Pepper SBP-box transcription factor, CaSBP13, plays a negatively role in drought response

JOURNAL=Frontiers in Plant Science

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2024.1412685

DOI=10.3389/fpls.2024.1412685

ISSN=1664-462X

ABSTRACT=<p>The SBP-box gene significantly influences plant growth, development, and stress responses, yet its function in pepper plants during drought stress remains unexplored. Using virus-induced gene silencing and overexpression strategies, we examined the role of <italic>CaSBP13</italic> during drought stress in plants. The results revealed that the expression of <italic>CaSBP13</italic> can be induced by drought stress. Silencing of <italic>CaSBP13</italic> in pepper notably boosted drought resistance, as evident by decreased active oxygen levels. Furthermore, the water loss rate, relative electrical conductivity, malondialdehyde content, and stomatal density were reduced in CaSBP13-silenced plants compared to controls. In contrast, <italic>CaSBP13</italic> overexpression in <italic>Nicotiana benthamiana</italic> decreased drought tolerance with elevated reactive oxygen levels and stomatal density. Additionally, ABA signaling pathway genes (<italic>CaPP2C</italic>, <italic>CaAREB</italic>) exhibited reduced expression levels in CaSBP13-silenced plants post drought stress, as compared to control plants. On the contrary, <italic>CaPYL9</italic> and <italic>CaSNRK2.4</italic> showed heightened expression in CaSBP13-sienced plants under the same conditions. However, a converse trend for <italic>NbAREB</italic>, <italic>NbSNRK2.4</italic>, and <italic>NbPYL9</italic> was observed post-four day drought in CaSBP13-overexpression plants. These findings suggest that <italic>CaSBP13</italic> negatively regulates drought tolerance in pepper, potentially via ROS and ABA signaling pathways.</p>