Transcriptional and physiological insights into calcium-mediated waterlogging tolerance in peach

Abstract

Waterlogging (WL) stress severely affects the growth and productivity of fruit crops. Cytosolic calcium (Ca²⁺) is recognized as a secondary messenger that initiates adaptive responses to environmental stresses. However, the mechanisms by which exogenously applied Ca²⁺ enhances WL tolerance remain poorly understood. In this study, we investigated whether exogenous Ca²⁺, applied as calcium chloride (CaCl₂) and calcium oxide nanoparticles (CaO-NPs), might mitigate WL-induced damage in peach (Prunus persica) seedlings. We found that both Ca²⁺ formulations significantly alleviated WL-induced growth inhibition, restored photosynthetic efficiency, and maintained root system architecture and metabolic activity. Two Ca²⁺ treatments markedly reduced intracellular superoxide (SOD) and hydrogen peroxide accumulation, thus attenuating membrane lipid peroxidation and electrolyte leakage. Hormonal profiling demonstrated that Ca²⁺ suppressed excessive abscisic acid and salicylic acid accumulation while restoring jasmonate homeostasis under WL conditions. Furthermore, at the transcriptional level, Ca²⁺ enhanced stress tolerance by upregulating the expression of genes encoding antioxidant (PpSOD; and peroxidase, PpPOD), photosynthetic (photosystem II subunit Q, PpPsbQ; and photosystem I subunit K, PpPsaK), and Ca²⁺ (CBL-interacting protein kinases, PpCIPK5 and PpCIPK11). In line with reduced oxidative stress, Ca²⁺ also adaptively downregulated genes related to the fermentative pathway (alcohol dehydrogenase, PpADH; and lactate dehydrogenase, PpLDH), indicating a shift away from anaerobic metabolism. Notably, comparative analysis revealed that ionic Ca²⁺ and CaO-NP treatments resulted in largely similar outcomes under WL conditions, with only marginal differences in some parameters. Taken together, these results indicate that Ca²⁺-associated signaling is a putative regulatory network underlying adaptive responses to WL stress in woody fruit crops.

Keywords

Ca²⁺ signaling / Hormonal regulation / Hypoxia / Peach / Photosynthetic efficiency / ROS homeostasis

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Funding

Agriculture Research System of China(CARS-30)

RIGHTS & PERMISSIONS

The Author(s)