Reproductive failure in XXXX under transient carbohydrate limitation: flowers and very young siliques are jettisoned and the meristem is maintained to allow successful resumption of reproductive growth.

@entity505 @entity958 @entity3158 @entity30403
UNASSIGNED: The impact of transient @entity505 depletion on reproductive growth in @entity958 was investigated by transferring long-photoperiod-grown plants to continuous darkness and returning them to a light-dark cycle. After two days of darkness, @entity505 reserves were depleted in reproductive sinks and RNA in situ hybridization of marker transcripts showed that @entity505 starvation responses had been initiated in the meristem, anthers and ovules. Dark treatments of two or more days resulted in a bare-segment phenotype on the floral stem, with 23-27 aborted siliques. These resulted from impaired growth of immature siliques, and abortion of mature and immature flowers. Depolarization of @entity30403 protein and increased DII-VENUS expression pointed to rapid collapse of auxin gradients in the meristem and inhibition of primordia initiation. After transfer back to a light-dark cycle, flowers appeared and formed viable siliques and seeds. A similar phenotype was seen after transfer to sub-compensation point irradiance or @entity3158 . It also appeared in a milder form after a moderate decrease in irradiance, and developed spontaneously in short photoperiods. We conclude that @entity958 inhibits primordia initiation and aborts flowers and very young siliques in C-limited conditions. This curtails demand, safeguarding meristem function and allowing renewal of reproductive growth when @entity505 becomes available again. This article is protected by copyright. All rights reserved.
