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ABA plays a central role in mediating the regulatory effects of nitrate on root branching in Arabidopsis
Author(s) -
Signora Laurent,
De Smet Ive,
Foyer Christine H,
Zhang Hanma
Publication year - 2001
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 - 10.1046/j.1365-313x.2001.01185.x
Subject(s) - mutant , arabidopsis thaliana , arabidopsis , microbiology and biotechnology , elongation , lateral root , chemistry , biology , biochemistry , gene , materials science , ultimate tensile strength , metallurgy
Summary The formation of lateral roots (LR) is a major post‐embryonic developmental event in plants. In Arabidopsis thaliana , LR development is inhibited by high concentrations of NO 3 – . Here we present strong evidence that ABA plays an important role in mediating the effects of NO 3 – on LR formation. Firstly, the inhibitory effect of NO 3 – is significantly reduced in three ABA insensitive mutants, abi4‐1 , abi4‐2 and abi5‐1 , but not in abi1‐1 , abi2‐1 and abi3‐1 . Secondly, inhibition by NO 3 – is significantly reduced, but not completely abolished, in four ABA synthesis mutants, aba1‐1 , aba2‐3 , aba2‐4 and aba3‐2 . These results indicate that there are two regulatory pathways mediating the inhibitory effects of NO 3 – in A. thaliana roots. One pathway is ABA‐dependent and involves ABI4 and ABI5, whereas the second pathway is ABA‐independent. In addition, ABA also plays a role in mediating the stimulation of LR elongation by local NO 3 – applications.