Brassinosteroid Biosynthetic Gene SlCYP90B3 Alleviates Chilling Injury of Tomato (Solanum lycopersicum) Fruits during Cold Storage

Abstract

Tomato is susceptible to chilling injury during cold storage. In this study, we found that low temperature promoted the expression of brassinosteroid (BR) biosynthetic genes in tomato fruits. The overexpression of SlCYP90B3 (SlCYP90B3-OE), a key BR biosynthetic gene, alleviated the chilling injury with decreased electrical conductivity and malondialdehyde. In SlCYP90B3-OE tomato fruits, the activities of antioxidant enzymes, including ascorbate peroxidase (APX), catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD), were markedly increased, while the activity of membranous lipolytic enzymes, lipoxygenase (LOX), and phospholipase D (PLD), were significantly decreased when compared with the wild-type in response to cold storage. Furthermore, the expression level of the cold-response-system component, SlCBF1, was higher in SlCYP90B3-OE fruits than in the wild-type fruits. These results indicated that SlCYP90B3 might be involved in the chilling tolerance of tomato fruits during cold storage, possibly by regulating the antioxidant enzyme system and SlCBF1 expression.

PscCYP716A1-Mediated Brassinolide Biosynthesis Increases Cadmium Tolerance and Enrichment in Poplar

“…The same mechanism also was reported in a recent investigation that the overexpression of the CPD gene involved in C-3 oxidase of the BR biosynthesis pathway significantly elevated the activities of antioxidant enzymes (SOD, POD, CAT, GR, and APX) to resist oxidative injury under drought stress (Zhou et al, 2016 ). When fruits were exposed to cold storage conditions, the SlCYP90B3 gene, which participates in the early stage of the C-22 α-hydroxylation in BR biosynthesis, increased the chilling tolerance of fruits through aggrandizing antioxidant system (Hu et al, 2022 ).…”

Brassinosteroids Improve Postharvest Quality, Antioxidant Compounds, and Reduce Chilling Injury in ‘Arrayana’ Mandarin Fruits under Cold Storage

“…Recently, it has been shown that BR is involved in the endogenous response to toleration of postharvest CI by increasing the synthesis of enzymes and antioxidant molecules, inhibiting protein degradation, and maintaining cellular energy status through signaling cascades with other hormones, which generates a reduction in the CI of the fruit [48,49]. In our experiment, the fruits with immersion in BR, regardless of the analogue, presented increased antioxidant activity (ABTS and DPPH radicals) and total phenol content (TPC) (Figure 5).…”