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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.)

Increased sink strength offsets the inhibitory effect of sucrose on sugarcane photosynthesis

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Author(s):
Ribeiro, Rafael V. ; Machado, Eduardo C. ; Magalhaes Filho, Jose R. ; Lobo, Ana Karla M. ; Martins, Marcio O. ; Silveira, Joaquim A. G. ; Yin, Xinyou ; Struik, Paul C.
Total Authors: 8
Document type: Journal article
Source: Journal of Plant Physiology; v. 208, p. 61-69, JAN 2017.
Web of Science Citations: 8
Abstract

Spraying sucrose inhibits photosynthesis by impairing Rubisco activity and stomatal conductance (g(s)), whereas increasing sink demand by partially darkening the plant stimulates sugarcane photosynthesis. We hypothesized that the stimulatory effect of darkness can offset the inhibitory effect of exogenous sucrose on photosynthesis. Source-sink relationship was perturbed in two sugarcane cultivars by imposing partial darkness, spraying a sucrose solution (50 mM) and their combination. Five days after the onset of the treatments, the maximum Rubisco carboxylation rate (V-cmax) and the initial slope of A-C-i curve (k) were estimated by measuring leaf gas exchange and chlorophyll fluorescence. Photosynthesis was inhibited by sucrose spraying in both genotypes, through decreases in V-cmax, k, g(s) and ATP production driven by electron transport (J(atp)). Photosynthesis of plants subjected to the combination of partial darkness and sucrose spraying was similar to photosynthesis of reference plants for both genotypes. Significant increases in V-cmax, g(s) and J(atp) and marginal increases in k were noticed when combining partial darkness and sucrose spraying compared with sucrose spraying alone. Our data also revealed that increases in sink strength due to partial darkness offset the inhibition of sugarcane photosynthesis caused by sucrose spraying, enhancing the knowledge on endogenous regulation of sugarcane photosynthesis through the source-sink relationship. (C) 2016 Elsevier GmbH. All rights reserved. (AU)

FAPESP's process: 08/57495-3 - Integrating physiological, morphological and anatomical traits to understand the differential sucrose yield in sugarcane genotypes
Grantee:Eduardo Caruso Machado
Support Opportunities: Program for Research on Bioenergy (BIOEN) - Thematic Grants