# Harpin Protien



## bombbudpuffa (Dec 22, 2008)

Heres a very interesting read I found.

*The Harpin Protein Discoveries*


The identification and isolation of Harpin Proteins came from basic research at Cornell University attempting to understand how plant pathogenic bacteria interact with plants. A first line of defense is the Hypersensitive Response (HR), a localized plant cell death at the site of infection. Cell death creates a physical barrier to movement of the pathogen and in some plants dead cells can release compounds toxic to the invading pathogen.

 Research had indicated that pathogenic bacteria were likely to have a single factor that was responsible for triggering the HR. A basic aim of the Cornell research was to identify a specific bacterial protein responsible for eliciting the HR. The target protein was known to be encoded by one of a group of bacteria genes called the Hypersensitive Response and Pathogenicity (hrp) gene cluster. The hrp cluster in the bacterium _Erwinia amylovora_ (_ea_), which causes fire blight in pear and apple, was dissected and a single protein was identified that elicited HR in certain plants. This protein was given the name Harpin and the corresponding gene designated hrpN. This was the first example of such a protein and gene identified from any bacterial species. 

 This research was done by Dr. Zhongmin Wei in the laboratory of Dr. Steven Beer at Cornell. The work was published in 1992 in an article in the journal Science. Early in the characterization of Harpin_ea_, it was discovered that Harpin could elicit disease resistance in plants and, surprisingly, increase plant growth.

 An important early finding about Harpin was that injections of purified Harpin Protein made a plant resistant to a subsequent pathogen attack, and in locations on the plant well away from the injection site. This meant that Harpin Protein triggers a Systemic Acquired Resistance (SAR), a well known plant defense mechanism that provides resistance to a variety of viral, bacterial, and fungal pathogens. 

 Another major discovery about Harpin Proteins was that sprayed topical application of them in small quantities would effectively activate plant defense responses. Importantly, these topical applications of Harpin did not elicit any visible HR. The effects of Harpin on disease resistance and growth, together with the simple means of application, provided the basis for commercializing Harpin Proteins. 




hxxp://www.planthealthcare.com/Ag/Overview/Harpin/Discovery


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## mister_terious (Aug 28, 2009)

:holysheep: I've used this product with dehydrating results on my garden. Am returning two of the three i ordered


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## umbra (Aug 28, 2009)

trichoderma bacteria is proven effective and readily available.


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## Mutt (Aug 28, 2009)

umbra said:
			
		

> trichoderma bacteria is proven effective and readily available.



yep, can be a good thing or a terribly bad thing in a garden...depends what your growing


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