Hadwiger L A
Department of Plant Pathology, Washington State University, Pullman, Washington 99163.
Plant Physiol. 1972 May;49(5):779-82. doi: 10.1104/pp.49.5.779.
The psoralen compounds, xanthotoxin and 4,5', 8-trimethylpsoralen, when activated, increased phenylalanine ammonia lyase (PAL) activity and the synthesis of pisatin in excised pea pods. Pods presoaked 1 hr with 4,5',8-trimethylpsoralen and then irradiated 4 minutes with 366 nanometer ultraviolet light had twice as much PAL activity 3 hours after irradiation and 12 times as much PAL activity 20 hours after irradiation as the pods of the water-treated control. Increases in PAL activity and pisatin synthesis were not obtained with 4,5',8-trimethylpsoralen, xanthotoxin, or 366 nanometer light treatment alone. 4,5',8-Trimethylpsoralen in combination with the irradiation treatment (366 nanometers) enhanced the rate at which l-leucine is incorporated into various fractions of soluble proteins in excised pods 8 hours after treatment. This treatment decreased the rate at which orotic acid is incorporated into RNA. The increase in PAL activity induced by irradiated psoralens was prevented when 6-methylpurine (0.5 milligram per milliliter) or cycloheximide (10 micrograms per milliliter) was applied immediately following the irradiation period. Possible functions of psoralen compounds in plants are discussed.
补骨脂素类化合物，即花椒毒素和4,5',8-三甲基补骨脂素，在被激活后，可提高苯丙氨酸解氨酶（PAL）的活性，并促进豌豆离体豆荚中植保素豌豆素的合成。用4,5',8-三甲基补骨脂素预浸泡1小时，然后用366纳米紫外线照射4分钟的豆荚，在照射后3小时的PAL活性是水处理对照组豆荚的两倍，在照射后20小时的PAL活性是其12倍。单独使用4,5',8-三甲基补骨脂素、花椒毒素或3,66纳米光处理均未使PAL活性和豌豆素合成增加。4,5',8-三甲基补骨脂素与照射处理（366纳米）相结合，可提高处理后8小时豌豆离体豆荚中L-亮氨酸掺入可溶性蛋白质各组分的速率。这种处理降低了乳清酸掺入RNA的速率。在照射期后立即施加6-甲基嘌呤（0.5毫克/毫升）或放线菌酮（10微克/毫升），可阻止补骨脂素经照射诱导的PAL活性增加。文中讨论了补骨脂素类化合物在植物中的可能功能。
