Figure 5

Proline content in AtOCD genotypes in response to low water potential or exogenous proline and proline metabolism gene expression. A. Seven-day-old seedlings of AtOCD mutants, RNAi and over-expression lines were transferred either to unstressed (−0.25 MPa), or to PEG-infused agar plates to impose low water potential (−1.2 MPa) for 96 h. Data are means ± S.E. (n = 6). One representative data set is shown out of four independent experiments performed. Asterisks indicate significantly different proline contents compared to the Col wild type (p ≤ 0.05). B. Proline content of p5cs1-4 and ocd-2/p5cs1-4 after 96 h at −1.2 MPa. Data are means ± S.E. (n = 6) combined from two independent experiments. Asterisks indicate significant difference between genotypes (p ≤ 0.05). C. Seedling proline content 96 h after transfer of seven-day-old seedlings to media containing 10 mM proline. Data are means ± SE (N = 3-4). D. Proline metabolism gene expression for seven-day-old seedlings transferred to either −0.25 MPa or −1.2 MPa media for 96 h. Data are means ± SE (N = 6) combined from two experiments. Asterisks indicate significant difference of mutant or overexpression line compared to Col wild type at the same water potential. In the axis labels, atocd indicates the atocd T-DNA mutants (atocd-1 left bar and atocd-2 right bar), OE indicates AtOCD overexpression lines (AtOCD OE-1 left bar, AtOCD OE-2 right bar) and p/o indicates the p5cs1-4/atocd-2 double mutant.