Plant materials and growth conditions

Rice (O. sativa) genetic materials used in this study are in the ZH11 genetic background, and the def8 mutants were generated by BIOGLE GeneTech (http://www.biogle.cn/). EE lines EE-9 and EE-16 were generated by transforming ZH11 with the construct proDEF8::_fDEF8-RFP/pCAMBIA1300. Rice plants were grown in paddy fields with heavy metal pollution. Alternatively, uniformly germinated seeds were planted in 96-well plates without the bottoms and kept growing in Yoshida solution (pH 5.8) at 28°C, 60% relative humidity with a 13-h light/11-h dark photoperiod.

Arabidopsis transgenic lines OE-1 and OE-2 were generated by transforming the construct 35S::_fDEF8-GFP/pCAMBIA1300 into Col-0 using the Agrobacterium tumefaciens-mediated floral dip method as described (Clough and Bent, 1998). Arabidopsis plants were grown at 21°C–23°C with 60% relative humidity and a 16-h light/8-h dark photoperiod.