
Altered Gene Expression during Auxin-Induced Root Development from Excised Mung Bean Seedlings
Author(s) -
Rajinder S. Dhindsa,
Guangyuan Dong,
Louis Lalonde
Publication year - 1987
Publication title -
plant physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.554
H-Index - 312
eISSN - 1532-2548
pISSN - 0032-0889
DOI - 10.1104/pp.84.4.1148
Subject(s) - auxin , mung bean , gene expression , lateral root , biology , microbiology and biotechnology , messenger rna , biochemistry , gene , chemistry , arabidopsis , horticulture , mutant
Changes in the pattern of protein synthesis and in the translatable mRNA population have been examined during auxin-induced root development from excised mung bean seedlings. Several proteins, predominantly of low molecular weight and high pI, as shown by two-dimensional polyacrylamide gel electrophoresis, are synthesized specifically by auxin-treated tissue. These auxin-induced proteins appear between 6 and 12 hours of auxin treatment, reach a maximum at 24 hours, and decline at 48 hours. Untreated seedlings (placed in Hoagland solution), known to produce small number of roots at the cut end probably due to endogeneous auxin accumulated at the cut end through basipetal transport, show low level synthesis of auxin-specific proteins. Antiauxin treatment that completely inhibits auxin-induced rooting also prevents the appearance of auxin-induced proteins. The induction of a group of three to four proteins appears to be specific to antiauxin treatment. In vitro translation of mRNA from auxin-treated tissue, but not of mRNA from antiauxin-treated tissue, yields several polypeptides of low molecular weight and high pI. Since the auxin-induced proteins precede root development and are synthesized transitorily, it is likely that they play some regulatory role during the initiation of root development. The result show that auxin-induced root formation involves altered gene expression.