HSP70‐16 and VDAC3 jointly inhibit seed germination under cold stress in Arabidopsis

Abstract

Abscisic acid (ABA) transport plays a crucial role in seed germination under unfavourable conditions such as cold stress. Both heat shock protein 70 (HSP70) and voltage‐dependent anion channel (VDAC) protein are involved in cold stress responses in Arabidopsis. However, their roles in seed germination with regard to ABA signaling remain unknown. Here we demonstrated that Arabidopsis HSP70‐16 and VDAC3 jointly suppress seed germination under cold stress conditions. At 4°C, both HSP70‐16 and VDAC3 facilitated the efflux of ABA from the endosperm to the embryo and thus inhibited seed germination. HSP70‐16 interacted with VDAC3 on the plasma membrane and in the nucleus, and the interplay between HSP70‐16 and VDAC3 activated the opening of the VDAC3 ion channel. Our work established a novel function of HSP70‐16 in seed germination under cold stress and a possible association of VDAC3 activity with ABA transportation from endosperm to embryo under cold stress conditions. This study reveals that HSP70‐16 interacts with VDAC3 and facilitates the opening of the VDAC3 ion channel, which influences ABA efflux from endosperm to embryo, thus negatively regulates seed germination under cold stress.

Genomic Survey of Heat Shock Proteins in Liriodendron chinense Provides Insight into Evolution, Characterization, and Functional Diversities

“…Recent studies have shown that the heat shock proteins are abundantly expressed under stress conditions such as a high temperature, drought, low temperature, and salt stress [ 24 , 29 , 33 , 34 ]. They maintain plant homeostasis by participating in various biological functions such as protein synthesis, folding, cellular, and cellular localization, and protein degradation [ 6 , 10 , 17 ].…”

“…The overexpression of the corresponding GhHSP24.7 homologous gene in Arabidopsis and tomato promoted a seed germination [ 28 ]. Two genes AtHSP70-16 and AtVDAC3 have been shown to promote an ABA efflux from endosperm to embryo under low-temperature conditions, thereby inhibiting seed germination [ 29 ]. The AtHSP90-mediated AtPIN1 distribution regulates auxin distribution, promoting a development in Arabidopsis [ 30 ].…”

Characterization of HSP70 family in watermelon (Citrullus lanatus): identification, structure, evolution, and potential function in response to ABA, cold and drought stress

“…Most grape VaHSP70s showed obvious stress regulation under cold conditions, among which VaHSP70-19 was continuously highly expressed under cold treatment, whereas other VaHSP70s were downregulated ( Liu et al, 2022 ). The levels of Arabidopsis AtHSP70s and the chaperone genes were upregulated after cold treatment, while AtHSP70-16 was negatively regulated in seed germination, which may be a protective mechanism against cold stress ( Ashraf et al, 2021 ). The expression of watermelon ClHSP70-3 , -4 and -5 was upregulated under cold stress, however, ClHSP70-6 and -8 were significantly downregulated at 3 and 6 h ( Figure 8B ).…”

Stripe Rust Effector Pst_9302 Inhibits Wheat Immunity to Promote Susceptibility

“…Arabidopsis AtVDAC1 regulates infection resistance to Agrobacterium tumefaciens . NbVDACs are involved in resistance to Pseudomonas cichorii [ 49 ]. Notably, VDACs also function in Bax-mediated cell death [ 50 , 51 ].…”