Fig. 4.

WEE1 represses lateral root formation: WEE^oe inhibits and loss-of-function alleles show increased lateral root formation. (A) Phenotypes of 10-d-old arabidopsis seedlings: wild type (WT), WEE1^oe (line #58) and wee1-1 (scale bar = 10 mm). (B) The relationship between mean total number of lateral roots and lateral root primordia (± s.e.) and mean primary root length (mm ± s.e.) for 10-d-old seedlings grown at 20 °C: wild type (WT), two WEE1 over-expressing lines (WEE1^oe), #58 and #61, and two T-DNA insertion lines wee1-1 and wee1-4. Significance levels are P-values from Student's t-tests between each genotype and WT. Root length was significantly reduced in WEE1^oe #58 and #61 compared with WT (*P < 0·05), but was not significantly different from WT (P > 0·05) in wee1-1 and wee1-4. Numbers of laterals and primordia were significantly different from WT in WEE1^oe #58 and #61 (***, P < 0·001) and wee1-1 (**, P < 0·02). Mean (± s.e.) rate of lateral root formation per millimetre of primary is indicated in brackets above each symbol (n =10; *, P < 0·05; ***, P < 0·001).