Abstract
Very long chain fatty acids (VLCFAs) are fatty acids that consist of 20 or more carbons. However, it remains unknown whether they function in controlling cell division and/or differentiation during continuous development of plants.
pasticcino2 (pas2) mutants exhibit pleiotropic phenotypes in aerial tissues, such as organ fusion, leaf curling and severe defects in overall growth. Previously Bach et al. (2008)* reported that PAS2 encodes 3-hydroxy-acyl-CoA dehydratase that is an essential and limiting enzyme in VLCFA synthesis. We found that Arabidopsis seedlings treated with an inhibitor of VLCFA synthesis displayed similar phenotypes to those of pas2 mutants; i.e., activation of cell division in the shoot apical meristem (SAM) and hypocotyls. Moreover, we revealed that VLCFA syntheses in the epidermis is prerequisite for controlling plant growth by limiting over-proliferation in the SAM and young leaf primordia. Taken together, we hypothesize that VLCFA synthesis in the epidermis constitutes a homeostatic system at the shoot apex and guarantees continuous organ formation in Arabidopsis.
*Bach et al. (2008) PNAS, 105, 14727-14731
