Figure 2.

Expression of Integrated Reporter Genes and Natural Auxin Response Genes in Wild-Type and nph4-1 Protoplasts.

(A) Arabidopsis mesophyll protoplasts were isolated from wild-type leaves containing a stably integrated DR5:GUS reporter gene and treated with the indicated concentration of 1-NAA for 20 to 22 h before GUS activities were measured. Standard errors are indicated. In some cases, error bars are not visible because of the small size of the error bars.

(B) Same as in (A), but protoplasts were isolated from nph4-1 leaves containing a stably integrated DR5:GUS reporter gene.

(C) Same as in (A), but protoplasts were isolated from wild-type leaves containing a stably integrated 2XD0:GUS reporter gene.

(D) Same as in (A), but protoplasts were isolated from nph4-1 leaves containing a stably integrated 2XD0:GUS reporter gene.

(E) Protoplasts were isolated from wild-type and nph4-1, arf6-2, arf8-2, and arf19-3 mutant leaves and treated with (+) or without (−) 1 μM 1-NAA for 20 to 22 h. Total RNA was isolated, and RT-PCR was used to test the expression levels of the natural IAA1 and IAA19 genes. Expression of the Arabidopsis actin (ACT7) natural gene was used as a control.

(F) Whole-cell extracts from wild-type and nph4-1 protoplasts mock treated or treated with 1 μM 1-NAA for 20 to 22 h were tested by protein gel blotting with an ARF7 antibody. Loading control is a nonspecific band detected in seedlings with the ARF7 antibody.