Different responses of transgenic Bt rice and conventional rice to elevated ozone concentration.

To assess the different sensitivity to ozone (O) between transgenic Bt Shanyou63 (Bt-SY63) and its nontransgenic counterpart Shanyou63 (SY63), the leaf gas exchange, yield, grain elements, and antioxidant enzymes were investigated by performing a pot experiment under ambient O concentration (A-O) and elevated O concentration (1.5 × A-O, E-O). Under A-O, the chlorophyll content and yield of Bt-SY63 were significantly lower than those of SY63, whereas the stomatal conductance (Gs), cellular CO concentration (Ci), and Fe, Zn concentration showed the opposite trends.