Department of Biological Sciences, Mankato State University, Mankato, Minnesota 56001.
Plant Physiol. 1986 Feb;80(2):305-9. doi: 10.1104/pp.80.2.305.
Chloroplasts, isolated from the primary leaves of 7-day-old seedlings, were incubated in vitro at 25 degrees C with 2-chloroethylphosphonic acid (ethephon) under light (0.16 milliwatts per square centimeter) and dark conditions. Ethephon at 1 micromolar (0.1445 ppm), 0.1 and 1 millimolar, or 5 microliters ethylene promoted the deterioration of chloroplasts, increased proteolysis, and reduced the chlorophyll content and PSI and PSII during 72 hours under both light and dark conditions. The decline in PSI and PSII occurred prior to a measurable loss of chlorophyll. The loss of photosynthetic activity affected by ethephon was initiated prior to 12 hours of incubation. After 24 hours in light, 0.1 millimolar (1.445 ppm) epthephon significantly reduced PSI and PSII and promoted the total free amino acid liberation in isolated chloroplasts. In darkness the rate of loss of PSI activity was about 50% of that in light. After 24 hours, in light at 1 millimolar epthephon, PSII activity was 55% of the control, yet nearly 90% of the chlorophyll remained, which indicates that the loss of thylakoid integrity was promoted by ethephon. Ethylene injected in the chloroplast medium at 5 microliters (0.22 micromolar per milliliter) reduced PSI by nearly 50% of the initial in 12 hours. In leaf sections floated in 5 microliters per milliliter suspension medium, a 36% loss of chlorophyll of the control in 36 hours was observed. Cycloheximide at 0.5 millimolar masked the effect of 1 millimolar ethephon and maintained the initial chlorophyll content during the 72 hour period.
叶绿体，从 7 天大幼苗的初生叶片中分离出来，在光照（0.16 毫瓦/平方厘米）和黑暗条件下，于 25℃下用 2-氯乙基膦酸（乙烯利）在体外孵育。1 微摩尔（0.1445ppm）、0.1 毫摩尔和 1 毫摩尔或 5 微升乙烯利促进叶绿体的恶化，增加蛋白水解，并在光照和黑暗条件下的 72 小时内降低叶绿素含量和 PSI 和 PSII。PSI 和 PSII 的下降发生在可测量的叶绿素损失之前。乙烯利影响的光合作用活性下降在孵育 12 小时之前开始。在光照下 24 小时后，0.1 毫摩尔（1.445ppm）乙烯利显著降低 PSI 和 PSII，并促进分离叶绿体中总游离氨基酸的释放。在黑暗中，PSI 活性的丧失速率约为光照的 50%。24 小时后，在光照下 1 毫摩尔乙烯利下，PSII 活性为对照的 55%，但几乎 90%的叶绿素仍然存在，这表明乙烯利促进了类囊体完整性的丧失。在叶绿体培养基中注入 5 微升（0.22 微摩尔/毫升）的乙烯，在 12 小时内将 PSI 减少到初始值的近 50%。在叶片切片中漂浮在 5 微升/毫升悬浮培养基中，在 36 小时内观察到对照物的叶绿素损失了 36%。0.5 毫摩尔的环己酰亚胺掩盖了 1 毫摩尔乙烯利的作用，并在 72 小时内维持了初始叶绿素含量。
