Abstract
Rape seedlings were acclimated to evaporative dehydration by exposure to repeated moderate water-deficit stress. The stress program started after 19 days of growth and consisted of three, 24-h stress periods interspersed with 24-h rewatering periods. After the third stress period the roots were harvested and microsomal membranes were isolated. Control plants were grown under equivalent conditions without stress (nonacclimated cells). Total lipids were extracted from the membranes and investigated with X-ray crystallography and polarization microscopy at different degrees of hydration and temperatures. In excess water, the membrane lipids from both acclimated and nonacclimated cells exhibited a cubic phase. The lipids from the nonacclimated cells formed a hexagonal (HII) phase on dehydration. The lipids from the acclimated cells behaved in a different way during dehydration, where the cubic phase was transformed to an L2 phase via an intermediate HII phase. At increasing temperatures, the hydrated cubic phase started to form an L2 phase at 30 °C and was fully converted to the liquid-type state at 42 °C. The mesomorphic phase behaviour is discussed in relation to membrane activity.Key words: water-deficit stress, microsomal membranes, X-ray crystallography, polarization microscopy.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.