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A molecular framework for the inhibition of Arabidopsis root growth in response to boron toxicity
Author(s) -
AQUEA FELIPE,
FEDERICI FERNAN,
MOSCOSO CRISTIAN,
VEGA ANDREA,
JULLIAN PASTOR,
HASELOFF JIM,
ARCEJOHNSON PATRICIO
Publication year - 2012
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.2011.02446.x
Subject(s) - cytokinin , meristem , abscisic acid , arabidopsis , auxin , microbiology and biotechnology , mitosis , cell growth , root hair , biology , cell division , growth inhibition , cell cycle , arabidopsis thaliana , toxicity , chemistry , botany , biochemistry , cell , shoot , gene , mutant , organic chemistry
Boron is an essential micronutrient for plants and is taken up in the form of boric acid (BA). Despite this, a high BA concentration is toxic for the plants, inhibiting root growth and is thus a significant problem in semi‐arid areas in the world. In this work, we report the molecular basis for the inhibition of root growth caused by boron. We show that application of BA reduces the size of root meristems, correlating with the inhibition of root growth. The decrease in meristem size is caused by a reduction of cell division. Mitotic cell number significantly decreases and the expression level of key core cell cycle regulators is modulated. The modulation of the cell cycle does not appear to act through cytokinin and auxin signalling. A global expression analysis reveals that boron toxicity induces the expression of genes related with abscisic acid (ABA) signalling, ABA response and cell wall modifications, and represses genes that code for water transporters. These results suggest that boron toxicity produces a reduction of water and BA uptake, triggering a hydric stress response that produces root growth inhibition.