Method for regulating cell death

Abstract

A method for regulating cell death in a plant, includes the steps of: transforming a plant cell with a polynucleotide containing a gene encoding DS9 or a homologue thereof or a part of the gene; and redifferentiating the transgenic plant cell to obtain a plant. The DS9 or the homologue thereof is an ATP-dependent Zn-type metalloprotease. The polynucleotide decreases or increases production of the ATP-dependent Zn-type metalloprotease in the plant cell, whereby cell death of a cell in the plant is promoted or suppressed.

What is claimed is:  
     
         1 . A method for regulating cell death in a plant, comprising the steps of: 
 transforming a plant cell with a polynucleotide containing a gene encoding DS9 or a homologue thereof or a part of the gene; and    redifferentiating the transformed plant cell to obtain a plant,    wherein the DS9 or the homologue thereof is an ATP-dependent Zn-type metalloprotease, and the polynucleotide decreases or increases production of the ATP-dependent Zn-type metalloprotease in the plant cell, whereby cell death of a cell in the plant is promoted or suppressed.    
     
     
         2 . A method according to  claim 1 , wherein the polynucleotide contains the gene encoding the DS9 or the homologue thereof or the part of the gene in an antisense orientation, whereby cell death of a cell in the plant is promoted.  
     
     
         3 . A method for producing a plant which is conferred with resistance to environmental stress, comprising the steps of: 
 transforming a plant cell with a polynucleotide containing a gene encoding DS9 or a homologue thereof or a part of the gene; and    redifferentiating the transformed plant cell to obtain a plant,    wherein the DS9 or the homologue thereof is an ATP-dependent Zn-type metalloprotease, and the polynucleotide decreases or increases production of the ATP-dependent Zn-type metalloprotease in the plant cell.    
     
     
         4 . A method according to  claim 3 , wherein the environmental stress is pathogen infection.  
     
     
         5 . A method according to  claim 3 , wherein the nucleotide contains the gene encoding the DS9 or the homologue thereof or the part of the gene in an antisense orientation.  
     
     
         6 . A method according to  claim 3 , wherein the homologue has a homology of about 70% or more with respect to an ATPase region of the DS9.  
     
     
         7 . A method for screening a selective inhibitor of a gene encoding DS9 or a homologue thereof, wherein the DS9 or the homologue thereof is an ATP-dependent Zn-type metalloprotease, comprising the steps of: 
 introducing a candidate inhibitor into a plant cell having a gene encoding the DS9 or the homologue thereof; and    identifying whether or not production of the DS9 or the homologue thereof is selectively decreased in the plant cell.