Effect of the transgenerational exposure to elevated CO2 on low temperature tolerance of winter wheat: Chloroplast ultrastructure and carbohydrate metabolism

Abstract

AbstractThe transgenerational effect of elevated atmospheric CO2 concentration (e[CO2]) on low temperature response in wheat is still little investigated, through the interaction of e[CO2], 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 CO2 concentration (a[CO2]) and e[CO2] (2014–2018) were investigated. The results indicated that the transgenerational exposure to e[CO2] 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[CO2] 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[CO2] 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[CO2] could improve low temperature tolerance of winter wheat, which provide novel insights to the response of wheat to future climate change.