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Engineering the expression level of cytosolic nucleoside diphosphate kinase in transgenic Solanum tuberosum roots alters growth, respiration and carbon metabolism
Author(s) -
Dorion Sonia,
Clendenning Audrey,
Rivoal Jean
Publication year - 2017
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.13431
Subject(s) - biology , biochemistry , nucleoside , population , nucleoside diphosphate kinase , enzyme , metabolism , demography , sociology
Summary Nucleoside diphosphate kinase ( NDPK ) is a ubiquitous enzyme that catalyzes the transfer of the γ‐phosphate from a donor nucleoside triphosphate to an acceptor nucleoside diphosphate. In this study we used a targeted metabolomic approach and measurement of physiological parameters to report the effects of the genetic manipulation of cytosolic NDPK ( NDPK 1) expression on physiology and carbon metabolism in potato ( Solanum tuberosum ) roots. Sense and antisense NDPK 1 constructs were introduced in potato using Agrobacterium rhizogenes to generate a population of root clones displaying a 40‐fold difference in NDPK activity. Root growth, O 2 uptake, flux of carbon between sucrose and CO 2 , levels of reactive oxygen species and some tricarboxylic acid cycle intermediates were positively correlated with levels of NDPK 1 expression. In addition, NDPK 1 levels positively affected UDP ‐glucose and cellulose contents. The activation state of ADP ‐glucose pyrophosphorylase, a key enzyme in starch synthesis, was higher in antisense roots than in roots overexpressing NDPK 1. Further analyses demonstrated that ADP ‐glucose pyrophosphorylase was more oxidized, and therefore less active, in sense clones than antisense clones. Consequently, antisense NDPK 1 roots accumulated more starch and the starch to cellulose ratio was negatively affected by the level of NDPK 1. These data support the idea that modulation of NDPK 1 affects the distribution of carbon between starch and cellulose biosynthetic pathways.