Figure 5.

Relation between TCP4, TCP20, and LOX2 expression. A, Wild-type plants were harvested 4 d and 2 weeks after sowing, and LOX2 expression was analyzed in quantitative PCR assays including three biological replicates of 20 seedlings per replicate. The graph depicts mean-normalized expression of LOX2, which increases dramatically between the two developmental time points. B, Statistical analysis of the correlation of TCP20 to TCP4 expression during Arabidopsis development. The correlation coefficient (−0.41) and P value (0.01) are indicated. The analysis was done using expression data from AtGenExpress and with STATISTICA 6.0 (Hill and Lewicki, 2007). C, Expression of the three class I TCPs TCP8, TCP20, and TCP22 and the class II TCP TCP4 at two different stages of Arabidopsis leaf development. In 4-d-old seedlings, TCP4 expression is lower than at day 14. Whereas TCP8 and TCP20 expression stays similar throughout the experiment, TCP22 expression behaves opposite to TCP4 expression. Consequently, the ratio of TCP4 to class I TCP expression changes in the course of leaf development. LOX2 expression increases from day 4 to day 14, which is in line with the idea that LOX2 expression is directly dependent on the ratio between TCP4 and class I TCP expression levels.