Overexpression of Seagrass Nucleotide Exchange Factor Gene <i>ZjFes1</i> Enhances Heat Tolerance in Transgenic <i>Arabidopsis</i>

Nucleotide exchange factors (NEFs) play an important role in plant abiotic stress response, but their characteristics and functions in seagrass have not been studied. <i>Zostera japonica</i> (<i>Z. japonica</i>) is one of the most widely distributed seagrass species in China and are distributed in subtropical and temperate coastal areas. <i>Z. japonica</i> is intertidal seagrass, which often undergoes heat stress during summer when the tide ebbs. Overexpression of <i>ZjFes1</i> in <i>Arabidopsis</i> results in an increase in heat tolerance. We found that ZjFes1 associates with ZjHsp70 <i>in vivo</i> by yeast two-hybrid and bimolecular fluorescence complementarity (BiFC). Overexpression of <i>ZjFes1</i> leads to selective reduction of <i>Hsp70</i> transcription and an increase in Hsp101. In conclusion, our results suggest that <i>ZjFes1</i> may be an active regulator of heat tolerance.