Inhibition Of Hypocrellin A On Botrytis Cinema

Hypocrellin A,(HA) is a natural fat-soluble photosensitizer with high optical activity and lowdark toxicity.Mainly applied in medicine field. Recently study was found that HA had a goodbiological control on a variety of fungi, plant diseases and insect pests which contribute it as a goodpotential of green light activated pesticide.Inhibition of HA on Botrytis cinema was preliminarily in this paper. Findings were asfollowing:1. The inhibition rate was73.9%and48.0%in12000Lx light and dark conditions respectivelywhen the concentration of HA was40mg.L-1. and concentraition for50%of maximaleffect(EC50)was17.16mg.L-1and69.21mg.L-1. The Minimal Inhibitory Concentraition(MIC) andMinimal Fungicidal Concentraition(MFC) was30mg.L-1and120mg.L-1in light while120mg.L-1and240mg.L-1in dark. So high inhibition of HA on B. cinema growth in light condition.2. After6h in the light (12000Lx), inhibition rate of40mg.L-1HA on B. cinema sporegermination was83.2%and the spore germination rate was11.8%in the end. When B. cinemaspore was treated with40mg.L-1HA for18h the spore germination rate was up to18.2%. So HAcould inhibit B. cinema spore germination effectively and inhibition increased with the increasingHA concentration.3. Cell relative conductivity improved with time went on when B. cinema was treated with HAin different concentrations in12000Lx light intensity. Conductivity reached26.5us.cm-1when thecell was treated with40mg.L-1HA after48h. With the increase of concentration of HA, protein,nucleic acid leakage degree significantly increased. In40mg.L-1HA, nucleic acid leakage was up to0.097and protein leakage degree was0.076. Visibly, HA can significantly increase cell membranepermeability of B. cinema.4. In the12000Lx light, when the concentration of HA was15mg.L-1, the scanning electronmicroscope (SEM) showed that mycelial morphology become expansion deformities, concave andconvex inequality and adhesion to each other. Results showed that the nucleus distorted seriously,the ribosome disappeared, a large number of protein particles flew out of the cell, mitochondriastructures were in chaos and cells had obvious cavities. When HA concentration was30mg.L-1the hyphae dehydrated, atrophied, ruptured, growing point disappeared; The nucleus, mitochondria,ribosomes and membranes were destroyed, intracellular material leaked in great quantities and cellslost the basic function and cytoactive. Therefore, HA can destroyed the morphology andultrastructure of B. cinema strongly.These results can provide the theoretical basis for HA which may be developed as a greenefficient biological pesticide in the future.