บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Fruit ripening and defence against pathogens-loss of resistance or grain of susceptibility.

Labavitch, J. M.;

ACIAR Proceedings Series Year: 1998 Issue: No. 80 Pages: 53-59 Ref: 40 ref.

1998

บทคัดย่อ

Fruit ripening and defence against pathogens-loss of resistance or grain of susceptibility.

Developing fruits exhibit general resistance to many pathogenic fungi. The natural defences of fruits fall into the same categories (preformed and induced, physical and biochemical) as the defence expressed by other plant organs. For many years plant pathologists have worked to understand the specific mechanisms of disease resistance and how their expression is controlled. These research efforts have gained importance in recent years as restrictions have been placed on the chemicals that have been used to control postharvest diseases because of consumer concerns about the effects of these chemicals on human health. Whether these concerns are warranted or not, they have put increasing pressure on efforts to develop more 'natural' means of control for local and export markets. When ripening begins, natural defences are no longer expressed (or are no longer effective) and the incidence of disease is high. When viewed from the perspective of angiosperm evolution, this increase in a fruits susceptibi

lity to pathogens can be seen as beneficial. The pathogen helps to free the mature seeds from the fruit so that their dispersal is enhanced. This kind of thinking leads us to consider whether the ripening-related decrease in fruit defences should be viewed as a loss of resistance or a gain of susceptibility. This is an important distinction. Postharvest pathologists must try to sustain the fruits defences while millions of years of evolution of the ripening process (with its associated alterations in gene expression, cell wall polymer integrity, membrane function, metabolic pathways, etc.) have brought a loss of defence capability. The idea that susceptibility is gained during ripening may imply that there are ripening-associated signals that trigger an active dismantling of defences. If this is so, then it might be possible to specifically block the gain of susceptibility without disrupting other aspects of ripening.