NITROGEN AND CARBON NUTRIENT AND METABOLITE SIGNALING IN PLANTS

Authors: CORUZZI, GLORIA - NEW YORK UNIVERSITY; BUSH, DANIEL

Submitted to: Plant Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/1/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary: Plant leaves capture light energy from the sun and transform that energy into a useful form in the process called photosynthesis. The primary product of photosynthesis are sugars and amino acids. Generally, 50 to 80 percent of these metabolites are exported from the leaf as nutrients that supply most of the edible parts of the plant such as fruit, grains, and tubers. In this review, we summarize recent results that show that sugars and amino acids are also key signal molecules that alter gene expression and, ultimately, plant growth. This represents a radical change in our understanding of how metabolites affect plant growth and our analysis will be used by academic and industry scientists to develop new methods to modify the nutritional value and/or yield of harvested tissues.

Technical Abstract: One of the defining features of multicellular growth is the need to partition resources among organ systems that specialize in diverse biological processes. The leaf is the principle site of energy and carbon acquisition while other organ systems carry out additional essential activities, such as water and ion uptake in roots, or reproduction in flowers. Many of these organs are composed of non-photosynthetic tissues systems that must import sugars and amino acids to support growth and development. The transport and allocation of resources between photosynthetic leaf tissue and import-dependent tissues is known as assimilate partitioning, and transporters in both tissue systems play key roles in mediating this complex process. Recent results have shown that gene expression of many important transporters is regulated by key nitrogen and carbon metabolites, such as glutamine (N) and sucrose (C). This review describes recent advances in dissecting the molecular mechanisms of plant nutrient and metabolite regulation of gene expression.