Effect of the transgenerational exposure to elevated CO<sub>2</sub> on low temperature tolerance of winter wheat: Chloroplast ultrastructure and carbohydrate metabolism
Hui Li, Shengqun Liu, Junhong Guo, Fulai Liu, Fengbin Song, Xiangnan Li
Abstract
Abstract The transgenerational effect of elevated atmospheric CO 2 concentration ( e [CO 2 ]) on low temperature response in wheat is still little investigated, through the interaction of e [CO 2 ], and low‐temperature stress has been reported in a single generation. Here, the low temperature‐induced modifications of chloroplast ultrastructure and carbohydrate metabolism in wheat after four generations continuously grown under ambient CO 2 concentration ( a [CO 2 ]) and e [CO 2 ] (2014–2018) were investigated. The results indicated that the transgenerational exposure to e [CO 2 ] increased the number of grana lamellae and the amounts of osmiophilic lipid droplets, attenuating the negative effect of low temperature on chloroplast ultrastructure. The transgenerational e [CO 2 ] enhanced the activities of antioxidant enzymes ( i.e . SOD, POD and CAT) and concentrations of osmotic substances ( i.e . proline and soluble sugar), which alleviated the low temperature‐induced oxidative damage to the chloroplast ultrastructure. In addition, transgenerational exposure of wheat to e [CO 2 ] increased activities of vacInv and cwInv, while decreased fructokinase activity, which affected the sucrose metabolism in wheat leaf. These findings elucidated that transgenerational exposure to e [CO 2 ] could improve low temperature tolerance of winter wheat, which provide novel insights to the response of wheat to future climate change.