Mechanistic Insights Into Trehalose-Mediated Cold Stress Tolerance in Rapeseed (Brassica napus L.) Seedlings

Ali Raza; Wei Su; Ziqi Jia; Dan Luo; Yi Zhang; Ang Gao; Muhammad Azhar Hussain; Sundas Saher Mehmood; Yong Cheng; Yan Lv; Xiling Zou

doi:10.3389/fpls.2022.857980

Mechanistic Insights Into Trehalose-Mediated Cold Stress Tolerance in Rapeseed (Brassica napus L.) Seedlings

Front Plant Sci. 2022 Mar 10:13:857980. doi: 10.3389/fpls.2022.857980. eCollection 2022.

Authors

Ali Raza¹, Wei Su¹, Ziqi Jia¹, Dan Luo¹, Yi Zhang¹, Ang Gao¹, Muhammad Azhar Hussain¹, Sundas Saher Mehmood¹, Yong Cheng¹, Yan Lv¹, Xiling Zou¹

Affiliation

¹ Key Laboratory of Biology and Genetic Improvement of Oil Crops, Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, China.

Abstract

Cold stress (CS) severely affects several physiological, biochemical, and molecular mechanisms and limits the growth and production of rapeseed (Brassica napus L.). Trehalose (Tre) acts as a growth modulator, which is extensively used to improve the tolerance to multiple plant stresses. Further, Tre also serves as an external force in inducing plant signaling molecules, regulating the expression of stress-responsive genes, and enhancing the CS tolerance in plants. Nevertheless, the importance of exogenous Tre in improving the CS tolerance in rapeseed is still unclear. Therefore, the current study was designed to get mechanistic insights into Tre-mediated CS tolerance in rapeseed seedlings. To explore the Tre role, we designed four treatments [control (CK), CK + 20 mM L^-1 Tre, Cold, and Cold + 20 mM L^-1 Tre] and three CS conditions (4, 0, and -4°C). The results showed that Tre treatments significantly mitigated the adverse effects of CS on the seedlings and increased the survival rate of Tre-treated seedlings under CS conditions. The exogenous Tre dramatically increased the contents of osmoprotectants, including the soluble sugar (SS), soluble protein (SP), and proline (Pro), and the activities of antioxidant enzymes, such as catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), and ascorbate peroxidase (APX) were also increased under CS conditions. Additionally, Tre decreased the malondialdehyde (MDA) contents to protect the rapeseed seedlings. Moreover, Tre also remarkably augmented the expression levels of antioxidant genes (CAT12, POD34, and FSD7), CS-responsive marker genes (CBF1, CBF2, CBF4, COR6.6, COR15, COR25, COL1, and KIN1), and Tre-biosynthesis genes (TPS4, TPS8, and TPS9). Briefly, exogenous Tre not only regulates the antioxidant and osmotic balance, but it also significantly participates in Tre metabolism and signaling network to improve the CS tolerance in rapeseed. Thus, Tre-induced supervisory connections between physiological or/and biochemical attributes provide information to dissect the mechanisms of Tre-mediated CS tolerance.

Keywords: abiotic stress; antioxidant defense system; chilling stress; gene expression; marker genes; osmoprotectants; trehalose metabolism.