1975 Volume 41 Issue 1 Pages 15-23
Spreading of cucumber mosaic virus in cowpea leaf tissues was investigated in relation to the formation of local lesions. The following results were obtained.
1) Local lesions appeared more slowly but the size was larger at 20C than at 30C.
2) Spreading of the virus from the epidermis to the second cell layer (adjacent to the epidermis) was faster at 30C than at 20C, judging from the experiment in which diluted HCl was treated on the epidermis for destroying epidermal functions. Spreading of virus from the epidermis to the third cell layer (adjacent to the second cell layer) was also faster at 30C than at 20C, judging from the experiment in which the epidermis were stripped (the second cell layer was naturally destroyed by this treatment).
3) The time of spreading of the virus from the second cell layer to the third cell layer was calculated and it was faster at 30C than at 20C, but was equal, under the same temperature, in both inoculations with virus particles and its nucleic acid.
4) Temperatures were changed from 30C to 20C or vice versa at the time of virus spreading from epidermis to second or third cell layer. Time of local lesion appearance and the lesion size under the altered temperature conditions confirmed the time-course of virus spreading through leaf cell layers mentioned above.
From these results, the mode of spreading of the virus in leaf tissues and the local lesion formation are discussed.