DNA encoding a plant deoxyhypusine synthase, a plant eukaryotic initiation factor 5A, transgenic plants and a method for controlling senescence programmed and cell death in plants
Regulation of expression of programmed cell death, including senescence, in plants is achieved by integration of a gene or gene fragment encoding senescence-induced deoxyhypusine synthase, senescence-induced eIF-5A or both into the plant genome in antisense orientation. Plant genes encoding senescence-induced deoxyhypusine synthase and senescence-induced eIF-5A are identified and the nucleotide sequences of each, alone and in combination are used to modify senescence in transgenic plants.
1. A vector comprising (a) an isolated DNA molecule encoding (-a-) a senescence-induced Arabidopsis deoxyhypusine synthase, and (b) regulatory sequences operatively linked to the DNA molecule such that the deoxyhypusine synthase is expressed in a plant cell transformed with the vector to achieve co-suppression.
2. A method for inhibiting the expression of an endogenous senescence-induced deoxyhypusine synthase gene in an Arabidopsis plant by co-suppression, said method comprising
(1) transforming Arabidopsis plant cells with the vector of claim 1 and
(2) growing said plant, whereby said DNA molecule is over-expressed and the endogenous senescence-induced deoxyhypusine synthase gene is inhibited by the expression of the DNA molecule encoding the exogenous senescence-induced deoxyhypusine synthase.
3. The method of claim 2 , wherein the regulatory sequences comprise a constitutive promoter.
4. A transgenic Arabidopsis plant cell comprising the vector of claim 1 .
5. A vector comprising (a) a DNA molecule encoding (-a-) a senescence-induced Arabidopsis deoxyhypusine synthase, wherein the DNA molecule comprises a polynucleotide having at least about 70% sequence identity with SEQ ID NO:5; and (b) regulatory sequences operatively linked to the DNA molecule such that the deoxyhypusine synthase is expressed in an Arabidopsis plant cell transformed with the vector to achieve co-suppression.
6. A method for inhibiting the expression of an endogenous senescence-induced deoxyhypusine synthase gene in an Arabidopsis plant by co-suppression, said method comprising.
(1) transforming Arabidopsis plant cells with the vector of claim 5 ; and
(2) growing said plant, whereby said DNA molecule is over-expressed and the endogenous senescence-induced deoxyhypusine synthase gene is inhibited by the expression of the DNA molecule encoding the exogenous senescence-induced deoxyhypusine synthase.
7. A transgenic Arabidopsis plant cell comprising the vector of claim 5 .
8. The method of claim 6 , wherein the regulatory sequences comprise a constitutive promoter.
9. The vector of claim 1 , wherein the senescence-induced Arabidopsis deoxyhypusine synthase has the sequence set forth in SEQ ID NO:6.
10. The method of any of claims 3 , and 8 , wherein the constitutive promoter is a fig wart mosaic virus 35S promoter, a cauliflower mosaic virus (CaMV) 35S promoter, a double fig wart mosaic virus 35S promoter, a double CaMV 35S promoter, or a MAS promoter.