Abstract
We have found that overexpression of BZF1, which is a member of the BZF subfamily of a B-box zinc finger family, confers enlargement of vegetative growth, increase in viability under severe drought condition, and improvement of irrigation efficiency in Arabidopsis. In the BZF1-overexpressed plants, transpiration was reduced and decrease of soil water content after stop of irrigation was delayed. Expression of BZF1 was not responsive to drought and ABA. In the BZF1-overexpressed plants, expression of genes related to drought tolerance was not enhanced and expression of genes in the central metabolism was generally reduced. BZF1 is possibly involved in the function of sink leaves. These results suggested that the overexpressed BZF1 confers improvement of drought adaptation of plants by its unique mode of action that is different from that of known regulatory factors, which improve the drought tolerance by enhancement of drought response and/or dehydration resistance.
