Pathogen related proteins of inequality are proteins are structurally diverse group of plant proteins that are toxic to invading fungal pathogen They are widely distributed in plants in trace amounts, but are produced in much greater concentration in pathogen attack on stress full. PR proteins are either extremely acidic or extremely basic and therefore a highly soluble and reactive. these are low molecular weight proteins which accumulate 2 significant level in infected plant tissues.

1. PATHOGEN
RELATED PROTEINS
SIJO.A, MSC.
JUNIOR MICROBIOLOGIST

2. INTRODUCTION
• Pathogen related proteins of inequality are proteins are structurally diverse group
of plant proteins that are toxic to invading fungal pathogen
• They are widely distributed in plants in trace amounts, but are produced in much
greater concentration in pathogen attack on stress full.
• PR proteins are either extremely acidic or extremely basic and therefore a highly
soluble and reactive.
• these are low molecular weight proteins which accumulate 2 significant level in
infected plant tissues.

3. • Major classes of PR proteins are :-
1. PR-1
2. PR-2( beta 1-3 glucanase)
3. PR-3(Chitinase)
4. PR-4(hevein like)
5. PR-5(thaumatin and like osmotin)
• The ability of hydrolytic enzyme to break chitin and glucan in the cell wall of
fungal pathogen has been exploited to develop crop resistance to pathogen
• Various chitinase genes of plant have been isolated and characterized.

4. • The first report was in tobacco for a bacterial chitinase gene obtained from soil
bacterium (Serratia marcescens) was stably integrated and expressed in tobacco
leaves.
• A basic chitinase gene of being under the control of strong constitutive promoter
of CaMV 35S has been constitutively expressed to high level in transgenic plants
of tobacco and brassica napus.
• This expression resulted in significant protection of plant from post emergent
damping off caused by the pathogen rhizoctonia
• In the case of B.napus, although the protection was a delay rather than complete
inhibition of symptoms, it was concluded that the level of protection was sufficient
to be economic significance in field situations.

5. • There have been no reports of increased resistance from expression of 1-3 Beta-
glucan gene along in transgenic plants. But glucanase jeans pent present in with
Titan Edge should fungal resistance in tobacco, tomato, carrot, etc