Effect of Exogenous Calcium on Tolerance of Winter Wheat to Cold Stress during Stem Elongation Stage

Low-temperature stress during stem elongation is a major factor limiting wheat yield. While calcium (Ca²⁺) is known to enhance stress tolerance, it's potential as an alternative to cold priming and the underlying mechanisms in wheat remains unclear. The current study assessed the effects of exogenous Ca²⁺ and calcium inhibitors on wheat growth and related physiology mechanisms under low-temperature stress. The results revealed that exogenous Ca²⁺ increased photosynthesis and antioxidant capacity, lowered cell membrane damage, and ultimately enhanced tolerance to low-temperature stress during the stem elongation stage, compared with the non-exogenous Ca²⁺ treatment. Moreover, exogenous Ca²⁺ induced endogenous Ca²⁺ content and triggered the upregulation of Ca²⁺ signaling and cold-responsive related genes. This study highlights the significance of exogenous Ca²⁺ in enhancing stress tolerance and contributing to wheat yield improvement under low-temperature stress.