| Abstract Detail
Mineral Nutrition Cao, Aiqin [1], Jain, Ajay [2], Baldwin, James C. [3], Raghothama, Kashchandra G [2]. Phosphate Starvation Induced Differential Regulation of Distinct Members of Arabidopsis 14-3-3 Family Reveals Functional Specificity. Phosphorus (P) is one of the essential macronutrient for plants growth and development. Low availability of soluble inorganic phosphate (Pi) triggers various adaptive responses of which allocation of photosynthates to non-Pi carbon compounds such as starch is pivotal. In this study, we report the role of Pi in the regulation of the expression of 14-3-3 isoforms in Arabidopsis. The effect of Pi deprivation was differential among the members of non-epsilon group ranging from a significant reduction in the transcripts of GRF3 to non-perceptible changes for other members. Relatively the suppressive effect of Pi-deficiency was more pronounced on some of the epsilon members. A concurrent increase in the transcript levels of GRF9 with an increase in the concentration of Pi in the medium and alleviation of suppressive effect of Pi deficiency by replenishment with Pi suggests a role of Pi in the regulation of this gene. Comparatively, Pi-deprivation at low temperature (4°C) or Fe and K deficiency did not reveal any effect on the abundance of GRF9 transcripts. These data suggest that the regulation of GRF9 is not only nutrient-specific but also conditional. Analyses of loss-of-function mutants of GRF9 revealed an increased accumulation of starch in the leaves and induction of higher order lateral roots. Whereas, transgenic lines overexpressing GRF9 showed an inverse relationship between the abundance of the transcripts and accumulation of starch in the leaves. The phosphoserine/threonine-binding consensus motif (RXXS/TXP) of 14-3-3s is present in four of the high-affinity phosphate transporters and other Pi starvation induced genes. The data presented here provide evidence that Pi plays an important role in the transcriptional regulation of 14-3-3 genes.
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1 - Purdue university, Horticulture and Landscape Architecture, 625 Agricultural Drive mall, West Lafayette, IN, 47907-1165, US
2 - Purdue University, Horticulture and Landscape Architecture
3 - Oregon State University, USDA/ARS
Keywords:
Phosphate
Arabidopsis
14-3-3 isoforms
GRF9.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P11024
Abstract ID:1911 |
