Gene/Protein
Disease
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Enzyme
Compound
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Disease
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Target Concepts:
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Query: UNIPROT:P50583 (
asymmetrical
)
12,197
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Auxin transport affects a variety of important growth and developmental processes in plants, including the regulation of shoot and root branching. The
asymmetrical
localization of auxin influx and efflux carriers within the plasma membrane establishes the auxin gradient and facilitates its transport. REH1, a rice EIR1 (Arabidopsis ethylene insensitive root 1)-like gene, is a putative auxin efflux carrier. Phylogenetic analysis of 32 members of the PIN family, taken from across different species, showed that in terms of evolutionary relationship, OsPIN1 is closer to the PIN1 family than to the
PIN2
family. It is, therefore, renamed as OsPIN1 in this study. OsPIN1 was expressed in the vascular tissues and root primordial in a manner similar to AtPIN1. Adventitious root emergence and development were significantly inhibited in the OsPIN1 RNA interference (RNAi) transgenic plants, which was similar to the phenotype of NPA (N-1-naphthylphalamic acid, an auxin-transport inhibitor)-treated wild-type plants. alpha-naphthylacetic acid (alpha-NAA) treatment was able to rescue the mutated phenotypes occurring in the RNAi plants. Overexpression or suppression of the OsPIN1 expression through a transgenic approach resulted in changes of tiller numbers and shoot/root ratio. Taken together, these data suggest that OsPIN1 plays an important role in auxin-dependent adventitious root emergence and tillering.
...
PMID:A PIN1 family gene, OsPIN1, involved in auxin-dependent adventitious root emergence and tillering in rice. 1608 36
As a fundamental and dynamic cytoskeleton network, microfilaments (MFs) are regulated by diverse actin binding proteins (ABPs). Villins are one type of ABPs belonging to the villin/gelsolin superfamily, and their function is poorly understood in monocotyledonous plants. Here, we report the isolation and characterization of a rice (Oryza sativa) mutant defective in VILLIN2 (VLN2), which exhibits malformed organs, including twisted roots and shoots at the seedling stage. Cellular examination revealed that the twisted phenotype of the vln2 mutant is mainly caused by
asymmetrical
expansion of cells on the opposite sides of an organ. VLN2 is preferentially expressed in growing tissues, consistent with a role in regulating cell expansion in developing organs. Biochemically, VLN2 exhibits conserved actin filament bundling, severing and capping activities in vitro, with bundling and stabilizing activity being confirmed in vivo. In line with these findings, the vln2 mutant plants exhibit a more dynamic actin cytoskeleton network than the wild type. We show that vln2 mutant plants exhibit a hypersensitive gravitropic response, faster recycling of
PIN2
(an auxin efflux carrier), and altered auxin distribution. Together, our results demonstrate that VLN2 plays an important role in regulating plant architecture by modulating MF dynamics, recycling of
PIN2
, and polar auxin transport.
...
PMID:VLN2 Regulates Plant Architecture by Affecting Microfilament Dynamics and Polar Auxin Transport in Rice. 2648 44
Hydrogen peroxide (H
2
O
2
) is the key factor in many physiological and metabolic processes in plants. During seed germination, exogenous H
2
O
2
application influences gravitropism and induces curvature of the primary root in grass pea and pea seedlings. However, it remains unclear whether and how this happens in the model plant Arabidopsis thaliana. In the present study, the effect of exogenous H
2
O
2
on the gravitropic response of primary roots during Arabidopsis seed germination was studied using histology and molecular biology approaches. Appropriate H
2
O
2
treatment not only restrained primary root growth, but also disrupted gravitropism and induced root curvature. Histological staining and molecular analysis demonstrated that exogenous H
2
O
2
correlated with lack of starch-dense amyloplasts in root tip columella cells, which ultimately results in the lack of gravisensing. Detection of calcium ion (Ca
2+
) by a fluorescent probe showed that Ca
2+
distribution changed and intracellular Ca
2+
concentration increased in H
2
O
2
-treated primary root, which was consistent with alterations in auxin distribution and concentration triggered by H
2
O
2
treatment. Furthermore, the normally polar localization of Pin-formed 1 (PIN1) and
PIN2
became uniformly distributed on root tip cell membranes after treatment with H
2
O
2
. This leads to speculation that the IAA signaling pathway was affected by exogenous H
2
O
2
, causing
asymmetrical
distribution of IAA on both sides of the primary root, which would influence the gravitropic response.
...
PMID:Exogenous hydrogen peroxide inhibits primary root gravitropism by regulating auxin distribution during Arabidopsis seed germination. 2977 64
