| RING (Really Interesting New Gene) E3 ligases are involved in regulating plant development during environmental stresses. Members of the RING ankyrin family, Xbat32, Xbat34 and Xbat35 , were examined for potential roles in regulating plant development. While xbat34 demonstrated drought tolerance and ABA (Abscisic Acid) sensitivity, a biological function could not be assigned to xbat35. xbat32 was salt sensitive and overproduced ethylene. Overproduction of ethylene in xbat32 contributed to its reduced lateral root phenotype. Lateral root production in xbat32 was stimulated by inhibition of ethylene perception. Inhibition of ethylene biosynthesis promoted lateral root production on pre-existing xbat32 roots but had no effect on new root growth. In addition to blocking ethylene, exogenous ABA treatment also stimulated lateral root production for xbat32, possibly by blocking the action of high ethylene. When individually coupled with auxin, ABA and silver nitrate acted synergistically to increase lateral root production in xbat32 seedlings. |
