Antisense Overexpression of Gγ Subunit CsGG3.1-2 Reduces Soluble Sugar Content and Chilling Tolerance in Cucumber

Abstract

Plant G protein γ subunits have multiple functions in growth and development processes and in abiotic stress responses. Few functions of Gγ in horticultural crops have been revealed thus far. In this study, the potential function of CsGG3.1-2, one of the two alternative splice variants of Gγ gene CsGG3.1 in cucumber (Cucumis sativus L.), was investigated using transgenic plants overexpressing antisense CsGG3.1-2 under the control of the 35S promoter. The tolerance to chilling stress in transgenic plants was significantly decreased. Cold stress-related physiological parameters and the expression of CBFs and their downstream target genes were then measured. Compared with WT, the maximum efficiency of photosystem II (Fv/Fm), antioxidative enzymes activities, soluble protein, and proline accumulation decreased significantly in transgenic plants treated with cold stress, whereas the malonaldehyde (MDA) content increased. However, the overexpression of antisense CsGG3.1-2 did not affect the induction of cold-inducible genes. Quantitative real-time PCR (qPCR) analysis showed the increased expression of CBF genes and their downstream target genes in transgenic plants, suggesting that CsGG3.1-2 affects cold responses via CBF-independent pathways in cucumber. At the same time, the sucrose and fructose contents decreased in transgenic plants under both normal and cold conditions. These findings suggest that soluble sugar deficiency is associated with chilling sensitivity in transgenic plants, and CsGG3.1-2 may have a role in regulating carbohydrate metabolism in cucumber.

Knockout CsRBOH5.1 causes global decrease of H3K4me3 on genes during recovery after cold stress acclimation, leading to acclimation failure

“…4; Extended Data Table 4). Previous study has found that the expression of CsICEs-CsCBFs-CsCORs under CS signi cantly enhanced in cucumber 19,20 . However, compared with unacclimated seedlings, none of them enhanced during recovery at 4 h after CS-ACC (Extended Data Table 4b), indicated that CsICEs-CsCBFs-CsCORs mainly responded to the basal cold tolerance and cannot maintain response during short recovery even for 4 h. We then compared the expression of these genes between WT and Csrboh5.1 in CK, R4h and R48h, respectively, and found that CsRBOH5.1 knockout signi cantly decreased the expression of CsICE1, CsICE1-like and CsCBF2 (Extended Data Fig.…”

Effects of Cerasus humilis (Bge). Sok. Rootstock on Peach Growth, Development, and Expression of Growth-Related Genes

“…The qPCR method [35] was used to determine gene expression levels. Primers were designed using Primer 5.0, as shown in Table 1, and the reference primer (actin) was adopted from Brandi et al [36].…”