油菜种子萌发期和形成期脂肪酶活性的动态变化

Dynamic Change of Lipases Activity during Post-germinative Growth and Seed Development in Brassica napus

探讨宁油16号油菜品种种子萌发过程中脂肪酶活性与苗生长速率之间的关系以及低、中、高含油量油菜品系角果、种子发育过程中脂肪酶活性与种子油份代谢之间的关系。结果显示:油菜种子萌发期的相对生长速率和脂肪酶的活性呈正相关;在种子形成前期、中期,角果皮和种子中都检测到了脂肪酶活性,此时脂肪酶维持叶绿体活力,从而保持了油脂的合成;在种子形成后期,脂肪酶主要降解种子中的油脂,此时,高含油量品系种子的脂肪酶活性比低含油量品系低。推测在种子萌发期,脂肪酶通过降解种子中存储的油脂为苗的生长发育提供了碳源和能量;在种子形成前期和后期,通过降解油脂影响着种子的发育及油份积累。

The correlation between the lipase activity and the relative growth rate of rapeseed in Ningyou 16 of Brassica napus was studied.Meanwhile,the correlations between the lipase activities and the oil metabolism of pod and rapeseed in three lines of Brassica napus with low,medium and high oil content were studied.There was positive correlation between the lipase activity and the relative growth rate of rapeseed during post-germinative growth.During the early and middle stage of the seed development,the lipase activity was detected in pericarps and seeds,and the lipases sustained the activity of chloroplasts by degrading the oil in the seeds.During the later stage of the seed development,the lipase activity in the seeds of the high oil content line was lower than that in the low oil content line.Taken together,the lipase offered carbon source and energy by degrading the oil in the seeds during post-germinative growth.Moreover,the lipases affected seed growth and seed oil accumulation by degrading the oil in the seeds during the early and later stage of seed development.