硼对油菜体内核酸代谢的影响

Effect of Boron on Nucleic Acid Metabolismin Brassica napUs L.

硼胁迫造成油菜植株生长异常，使幼苗干物重显著下降；而幼苗叶片和花药内ＲＮａｓｅ活性明显增强，ＲＮＡ的分解加剧，ＲＮＡ和ＤＮＡ含量均下降，引起蛋白质的合成受阻，可溶性蛋白质含量急剧减少。这说明缺硼或硼过量时，植物体内核酸分解加剧是核酸含量下降的一个重要原因。

Solution culture and POt experi-ments were conducted to study the ef-fects of boron stress( boron deficiencyand boron toxlclty) on nucleic acidmetabolism in rapeseed(Brassica napusL.cv. Ning You No.8) plants. The re-sults showed that boron-siressed rapeplants grew abnormally.The dryweightsunder low boron andexcesslveboron conditions were lower than thoseof control plants,to winch appropriate level of boron was provided(Table1). On the other hand, the activity ofRNase in leaves and anthers were in-creased markedly(Figs. 3, 4). As aresult, the degradation of RNA wasenhanced, and their contents were reduced, the contents of DNA also de-clined(Figs.1, 2). Furthermore, thesynthesis of protein was depressed(Figs. 5, 6). These results indicatethat boron deficiency and toxicity de-creases nuclelc acid content mainlythrough the acceleration of the degra-dation of RNA.