Induction of ethylene synthesis and lipid peroxidation in damaged or TMV-infected tobacco leaf tissues by light.

摘要

The effect of light on ethylene and ethane production in damaged leaf tissues was investigated. When whole leaves of tobacco cv. Samsun NN were damaged with liquid nitrogen, the ethylene formation was the highest, if 100% of leaves were injured and were kept in the light, the lowest when leaves after 100% injury were kept in darkness. Ethane production (lipid peroxidation) could be detected only in damaged, but not in control leaves, and was much higher in light than in darkness. In addition, there was a strong degradation of chlorophyll of damaged leaves kept in light. In light aminoethoxy-vinylglycine (AVG) inhibited ethylene formation in control, non-damaged whole leaves effectively, but in leaves with 100% damage the inhibitory effect was much weaker and similar to the effect of propyl gallate (PG), a free radical scavenger. Both AVG and PG treatments decreased ethylene formation by control leaf discs and discs with 100% damage. Ethane production was significantly inhibited by PG and slightly by AVG in the case of 100% damage. Tiron, another free radical scavenger gave similar results on leaf discs as PG did. Paraquat (methylviologen, Pq), as a photosynthesis inhibiting and reactive oxygen species (ROS) producing herbicide produced a large amount of ethylene and ethane in light but very small amount in darkness. In accordance, tobacco mosaic virus (TMV) infection on the necrotic host resulted in significantly larger amount of ethylene and ethane formation in light than in darkness. We conclude that ethylene and ethane production of damaged plant tissues is strongly induced by light and ROS that are involved in this induction.CAS Registry Numbers 74-85-1