Transfer and expression of the Bacillus branched-chain alpha-oxo acid decarboxylase A and B genes in the tomato Lycopersicon esculentum var. Roma

ngineering of higher plants for increased cold tolerance will require the chemical modification of membrane fluidity in both organelles and in the cytoplasm of plants. Membrane fluidity is mainly dependent on the phase transition temperature of membrane phospholipids, which is determined by the ratio or saturated and unsaturated straight chain fatty acids present in the membrane. A small number of microorganisms utilize branched-chain fatty acids (BCFA) instead of unsaturated fatty acids as their membrane constituents. Microorganisms with elevated levels of BCFA were found to grow under stress conditions such as suboptimal temperature and hydrostatic pressure. BCFA were found to be present in plants such as Nicoriana tabacum and Antirrhinum majus. One of the key enzymes facilitating synthesis of BCFA in Bacillus subtilis 168s is the branched-chain...