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

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.

Comprehensive resistance evaluation of 15 blueberry cultivars under high soil pH stress based on growth phenotype and physiological traits

“…When osmotic balance is disrupted, plants maintain cellular osmotic pressure by accumulating substances, such as SS and SP (Xiong & Zhu, 2002;Kanu et al, 2019). In the present study, similar to other stress studies (Karimi & Salimi, 2021;Raza et al, 2022;Zhu et al, 2022a), the MDA content in the leaves of the 15 blueberry cultivars increased under the high soil pH stress conditions, and significant differences among the different cultivars (Figure 4A). The SS and SP contents in the leaves of most blueberry cultivars also increased to varying degrees (Figures 4B, C).…”

Melatonin-mediated temperature stress tolerance in plants

“… 5 , 6 , 11 To cope with temperature stress, plants modify their morphology, physiology, biochemistry, and gene expression, which alters their growing activities to grow and tolerate HS and CS conditions. 5 , 6 , 11 , 15 Temperature extremes (HS and CS) can cause overgeneration of reactive oxygen species (ROS) viz singlet oxygen ( 1 O 2 ), hydroxyl (OH) radicals, superoxide (O 2 − ), and hydrogen peroxide (H 2 O 2 ). 16 , 17 Especially, ROS are exceptionally sensitive to cellular objects and can cause critical oxidative impairment to metabolic events and thus restricting plant growth and development under temperature stress.…”

Exogenous melatonin confers cold tolerance in rapeseed (Brassica napus L.) seedlings by improving antioxidants and genes expression

“…It is found that MEL and its metabolites directly regulate the transcription level of antioxidant enzyme genes to increase stress tolerance in plants. 5 , 6 , 12 The proportion of Cu/Zn SOD enzyme in SOD enzyme is the largest, especially in the active oxygen scavenging enzyme system, which is closely connected with cold, saline-alkali, and other stress tolerance in plants. 38 , 39 Studies have shown that ICE-CBF-COR transcriptional network is critical in the process of cold acclimation.…”