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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Exposure of Catasetum fimbriatum aerial roots to light coordinates carbon partitioning between source and sink organs in an auxin dependent manner

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Author(s):
Rayner Oliveira, Paulo Marcelo [1] ; Rodrigues, Maria Aurineide [1] ; Goncalves, Ana Zangirolame [1] ; Kerbauy, Gilberto Barbante [1]
Total Authors: 4
Affiliation:
[1] Univ Sao Paulo, Inst Biociencias, Dept Bot, BR-05508900 Sao Paulo, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Plant Physiology and Biochemistry; v. 135, p. 341-347, FEB 2019.
Web of Science Citations: 0
Abstract

Light energy is essential for carbon metabolism in plants, as well as controlling the transport of metabolites between the organs. While terrestrial plants have a distinct structural and functional separation between the light exposed aerial parts and the non-exposed roots, epiphytic plants, such as orchids, have shoots and roots simultaneously fully exposed to light. The roots of orchids differ mainly from non-orchidaceous plants in their ability to photosynthesize. Since the roots of Catasetum fimbriatum can synthesize auxin which is acropetally transported to the shoot region, we decided to investigate whether: (1) light treatment of C. fimbriatum roots raises the auxin levels in the plant; and (2) distinct auxin concentrations can change the source-sink relationships, altering the amounts of sugars and organic acids in leaves, pseudobulbs and roots. Among the organs studied, the roots accumulated the highest concentrations of indole-3-acetic-acid (IAA); and when roots were exposed to light, IAA accumulated in the leaves. However, when polar auxin transport (PAT) was blocked with N-(1-Naphthyl)phthalamic acid (NPA) treatment, a significant accumulation of sugars and organic acids occurred in the pseudobulbs and leaves, respectively, suggesting that auxin flux from roots to shoots was involved in carbon partitioning of the aerial organs. Considering that C. fimbriatum plants lose all their leaves seasonally, it is possible the roots are a substituting influence on the growth and development of this orchid during its leafless period. (AU)

FAPESP's process: 16/09699-5 - Nitrogen metabolism and its interaction with the Crassulacean acid metabolism (CAM) in Guzmania monostachia (Bromeliaceae): a physiological and molecular approach
Grantee:Ana Zangirólame Gonçalves
Support Opportunities: Scholarships in Brazil - Post-Doctoral