The GH3 Protein from the Clubroot Pathogen Plasmodiophora brassicae Causes Hormone-Related Phenotypes in Arabidopsis thaliana
In the genome of the obligate biotrophic protist Plasmodiophora brassicae , which causes clubroot disease in the Brassicaceae family, a single gene was identified with homology to the group of GH3 proteins synthesizing amino acid conjugates with carboxylic acids. In comparison to plant members the P...
Saved in:
Published in | Journal of plant growth regulation Vol. 43; no. 8; pp. 2715 - 2738 |
---|---|
Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
New York
Springer US
01.08.2024
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | In the genome of the obligate biotrophic protist
Plasmodiophora brassicae
, which causes clubroot disease in the Brassicaceae family, a single gene was identified with homology to the group of GH3 proteins synthesizing amino acid conjugates with carboxylic acids. In comparison to plant members the
P. brassicae
GH3 protein seems to be very promiscuous with respect to the substrates converted. In vitro assays showed conversion of three different auxins (indole-3-acetic, IAA; indole-propionic, IPA; and indole-3-butyric acids, IBA), jasmonic acid (JA) and also 12-oxo-phytodienoic acid (OPDA). Auxin and Methyl-JA responsive elements were found in the promoter sequence of
PbGH3
. For further analysis
Arabidopsis thaliana
was transformed with
PbGH3
. Seedlings with confirmed constitutive PbGH3 protein production were grown to adult plants that were shown to produce fewer inflorescences per plant. Growth on 10 µM IAA or JA levels also altered the phenotype of the seedlings, but not so much between wild types and transgenic lines. The hormone profiles in seedlings and adult plants were examined for IAA, JA, OPDA, and respective conjugates. Transgenic seedlings displayed changes that could be partially attributed to the overexpression of a
GH3
gene like lower levels of free IAA and the JA precursor
cis
-OPDA under control conditions, and higher levels of some auxin conjugates accumulated after IAA treatment compared to the corresponding wild types. However, the hormone patterns in adult plants were more complex and varied based on different tissue types analyzed. After inoculation with
P. brassicae
the transgenic plants did not show any changes in infection rate and disease index, but had higher shoot and lower root weight in infected plants compared to controls. Based on the above findings we discuss a role for PbGH3 during pathogenesis. |
---|---|
ISSN: | 0721-7595 1435-8107 |
DOI: | 10.1007/s00344-024-11300-3 |