GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

PMID:19151132

From GONUTS
Jump to: navigation, search
Citation

Chen, CN, Chen, HR, Yeh, SY, Vittore, G and Ho, TH (2009) Autophagy is enhanced and floral development is impaired in AtHVA22d RNA interference Arabidopsis. Plant Physiol. 149:1679-89

Abstract

Autophagy is an intracellular process in which a portion of cytoplasm is transported into vacuoles for recycling. Physiological roles of autophagy in plants include recycling nutrients during senescence, sustaining life during starvation, and the formation of central digestive vacuoles. The regulation of autophagy and the formation of autophagosomes, spherical double membrane structures containing cytoplasm moving toward vacuoles, are poorly understood. HVA22 is a gene originally cloned from barley (Hordeum vulgare), which is highly induced by abscisic acid and environmental stress. Homologs of HVA22 include Yop1 in yeast, TB2/DP1 in human, and AtHVA22a to -e in Arabidopsis (Arabidopsis thaliana). Reverse genetics followed by a cell biology approach were employed to study the function of HVA22 homologs. The AtHVA22d RNA interference (RNAi) Arabidopsis plants produced small siliques with reduced seed yield. This phenotype cosegregated with the RNAi transgene. Causes of the reduced seed yield include short filaments, defective carpels, and dysfunctional pollen grains. Enhanced autophagy was observed in the filament cells. The number of autophagosomes in root tips of RNAi plants was also increased dramatically. The yop1 deletion mutant of Saccharomyces cerevisiae was used to verify our hypothesis that HVA22 homologs are suppressors of autophagy. Autophagy activity of this mutant during nitrogen starvation increased in 5 min and reached a plateau after 2 h, with about 80% of cells showing autophagy, while the wild-type cells exhibited low levels of autophagy following 8 h of nitrogen starvation. We conclude that HVA22 homologs function as suppressors of autophagy in both plants and yeast. Potential mechanisms of this suppression and the roles of abscisic acid-induced HVA22 expression in vegetative and reproductive tissues are discussed.

Links

PubMed PMC2663764 Online version:10.1104/pp.108.131490

Keywords

Arabidopsis/cytology; Arabidopsis/genetics; Arabidopsis/growth & development; Arabidopsis/ultrastructure; Arabidopsis Proteins/genetics; Arabidopsis Proteins/metabolism; Autophagy; Chromosome Segregation/genetics; Flowers/cytology; Flowers/genetics; Flowers/growth & development; Gene Deletion; Gene Expression Regulation, Plant; Membrane Transport Proteins/metabolism; Multigene Family/genetics; Phenotype; Plants, Genetically Modified; Pollen/cytology; Pollen/growth & development; Pollen/ultrastructure; RNA Interference; Saccharomyces cerevisiae/cytology; Saccharomyces cerevisiae Proteins/metabolism; Seeds/cytology; Seeds/ultrastructure; Suppression, Genetic; Transgenes

Significance

Annotations

Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status

ARATH:HA22D

acts_upstream_of_or_within

GO:0009555: pollen development

ECO:0000315: mutant phenotype evidence used in manual assertion

P

Seeded From UniProt

complete

ARATH:HA22D

acts_upstream_of_or_within

GO:0009908: flower development

ECO:0000315: mutant phenotype evidence used in manual assertion

P

Seeded From UniProt

complete

ARATH:HA22D

acts_upstream_of_or_within

GO:0010507: negative regulation of autophagy

ECO:0000315: mutant phenotype evidence used in manual assertion

P

Seeded From UniProt

complete


See also

References

See Help:References for how to manage references in GONUTS.