Developmental and environmental regulation of anthocyanin pigmentation in wheat tissues transformed with anthocyanin regulatory genes.

摘要

Cell autonomous anthocyanin pigmentation, produced by the anthocyanin regulatory genes B and C1 controlled by the constitutive CaMV35s promoter (pBC1-7), was used to optimize biolistic gene delivery into embryogenic wheat cv. Chris scutellum cultures. Intensely pigmented callus cells were observed 24 h post bombardment but these cells did not continue to divide and were developmentally terminal. A population of non-expressing cells generated transgenic sectors which showed light-dependent anthocyanin pigmentation. Anthocyanin pigmentation was suppressed in regenerating shoot cultures but reverted to light-dependent production in the pericarp of developing seeds. Similarly, following microtargeted gene delivery into apical meristems, anthocyanin production was developmentally suppressed in leaf base meristems but prominent anthocyanin sectors developed in mature tissues beyond this region and persisted throughout leaf growth. In three developmental situations, callus proliferation, plant regeneration, and leaf growth, perpetuation of cells with anthocyanin regulator genes under the control of constitutive promoters was dependent on a higher level of regulation to suppress pigmentation at developmentally sensitive stages of meristematic activity.These findings provide additional evidence that the anthocyanin regulatory genes may be responsive to a variety of developmental and environmental stimuli.