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Function of Arabidopsis hexokinase-like1 as a negative regulator of plant growth
A recent analysis of the hexokinase (HXK) gene family from Arabidopsis revealed that three hexokinase-like (HKL) proteins lack catalytic activity, but share about 50% identity with the primary glucose (glc) sensor/transducer protein AtHXK1. Since the AtHKL1 protein is predicted to bind glc, although...
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Formato: | Texto |
Lenguaje: | English |
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Oxford University Press
2009
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2755033/ https://www.ncbi.nlm.nih.gov/pubmed/19706780 http://dx.doi.org/10.1093/jxb/erp252 |
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author | Karve, Abhijit Moore, Brandon d. |
author_facet | Karve, Abhijit Moore, Brandon d. |
author_sort | Karve, Abhijit |
collection | PubMed |
description | A recent analysis of the hexokinase (HXK) gene family from Arabidopsis revealed that three hexokinase-like (HKL) proteins lack catalytic activity, but share about 50% identity with the primary glucose (glc) sensor/transducer protein AtHXK1. Since the AtHKL1 protein is predicted to bind glc, although with a relatively decreased affinity, a reverse genetics approach was used to test whether HKL1 might have a related regulatory function in plant growth. By comparing phenotypes of an HKL1 mutant (hkl1-1), an HXK1 mutant (gin2-1), and transgenic lines that overexpress HKL1 in either wild-type or gin2-1 genetic backgrounds, it is shown that HKL1 is a negative effector of plant growth. Interestingly, phenotypes of HKL1 overexpression lines are generally very similar to those of gin2-1. These are quantified, in part, as reduced seedling sensitivity to high glc concentrations and reduced seedling sensitivity to auxin-induced lateral root formation. However, commonly recognized targets of glc signalling are not apparently altered in any of the HKL1 mutant or transgenic lines. In fact, most, but not all, of the observed phenotypes associated with HKL1 overexpression occur independently of the presence of HXK1 protein. The data indicate that HKL1 mediates cross-talk between glc and other plant hormone response pathways. It is also considered Whether a possibly decreased glc binding affinity of HKL1 could possibly be a feedback mechanism to limit plant growth in the presence of excessive carbohydrate availability is further considered. |
format | Text |
id | pubmed-2755033 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2009 |
publisher | Oxford University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-27550332009-10-02 Function of Arabidopsis hexokinase-like1 as a negative regulator of plant growth Karve, Abhijit Moore, Brandon d. J Exp Bot Research Papers A recent analysis of the hexokinase (HXK) gene family from Arabidopsis revealed that three hexokinase-like (HKL) proteins lack catalytic activity, but share about 50% identity with the primary glucose (glc) sensor/transducer protein AtHXK1. Since the AtHKL1 protein is predicted to bind glc, although with a relatively decreased affinity, a reverse genetics approach was used to test whether HKL1 might have a related regulatory function in plant growth. By comparing phenotypes of an HKL1 mutant (hkl1-1), an HXK1 mutant (gin2-1), and transgenic lines that overexpress HKL1 in either wild-type or gin2-1 genetic backgrounds, it is shown that HKL1 is a negative effector of plant growth. Interestingly, phenotypes of HKL1 overexpression lines are generally very similar to those of gin2-1. These are quantified, in part, as reduced seedling sensitivity to high glc concentrations and reduced seedling sensitivity to auxin-induced lateral root formation. However, commonly recognized targets of glc signalling are not apparently altered in any of the HKL1 mutant or transgenic lines. In fact, most, but not all, of the observed phenotypes associated with HKL1 overexpression occur independently of the presence of HXK1 protein. The data indicate that HKL1 mediates cross-talk between glc and other plant hormone response pathways. It is also considered Whether a possibly decreased glc binding affinity of HKL1 could possibly be a feedback mechanism to limit plant growth in the presence of excessive carbohydrate availability is further considered. Oxford University Press 2009-10 2009-08-25 /pmc/articles/PMC2755033/ /pubmed/19706780 http://dx.doi.org/10.1093/jxb/erp252 Text en © 2009 The Author(s). This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.5/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. This paper is available online free of all access charges (see http://jxb.oxfordjournals.org/open_access.html for further details) |
spellingShingle | Research Papers Karve, Abhijit Moore, Brandon d. Function of Arabidopsis hexokinase-like1 as a negative regulator of plant growth |
title | Function of Arabidopsis hexokinase-like1 as a negative regulator of plant growth |
title_full | Function of Arabidopsis hexokinase-like1 as a negative regulator of plant growth |
title_fullStr | Function of Arabidopsis hexokinase-like1 as a negative regulator of plant growth |
title_full_unstemmed | Function of Arabidopsis hexokinase-like1 as a negative regulator of plant growth |
title_short | Function of Arabidopsis hexokinase-like1 as a negative regulator of plant growth |
title_sort | function of arabidopsis hexokinase-like1 as a negative regulator of plant growth |
topic | Research Papers |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2755033/ https://www.ncbi.nlm.nih.gov/pubmed/19706780 http://dx.doi.org/10.1093/jxb/erp252 |
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