脱壁酶液诱导植物细胞产生过氧化物酶抑制因子的研究

以烟草(+)天仙子杂交种愈伤组织、苜蓿和小麦愈伤组织为实验材料,用愈创木酚法测定过氧化物酶(EC.1.11.7 POD)活性,首次报道了用分离原生质体的脱壁酶液能够诱导植物细胞产生POD 抑制因子,所试材料经脱壁酶液处理后均测不出POD 活性,并且对POD活性具有抑制作用。此类POD 抑制因子是小分子物质,具有较强的热稳定性,一些迹象表明它们不是酚类物质。POD 抑制因子可能是通过影响POD 催化合成的初始反应产物的稳定性,来达到其抑制效能。不同种属来源植物细胞产生的POD 抑制因子在抑制作用上无明显差异。至于POD 抑制因子的稳定性,在原生质体培养难易程度不同的植物材料间有差异。文中讨论了POD 抑制因子的产生和清除对培养原生质体细胞壁的再生修复及对培养状况的影响。

PRODUCTION OF PEROXIDASE INHIBITORS FROM PLANT CELLS INDUCED BY CELL WALL DIGESTION ENZYMES

With the experimental materials ofHyoscyamus muticus(+)Nicotiana taba-cum somatic hybrid calli (N(+)H-c),al-falfa(Medicago sativa L.)calli,and wheat(Triticum aestivum L.)calli,and withthe guaiacol test to determine peroxidases(EC.1.11.7 POD)activity,it was foundthat the enzyme solution used for proto-plast isolation could induce the productionof POD inhibitors from plant cells.Theresults showed as follows:For all plantmaterials treated with the enzyme solution,the POD activity was undetectable in theirextract.POD inhibitors were small mole-cular substance,and were considerably sta-ble for heat.Evidences showed that it wasquite impossible for POD inhibitors to bephenolic compounds.The inhibition effectof POD inhibitors acted on the initialproducts catalyzed by POD.POD inhibi-tors from different plant species had nodifference in inhibition ability.It wasalso noticed that POD inhibitors were un-stable in the extract of N(+)H-c,whichwere derived from protoplast culture;inthe calli extract of wheat,which was re-calcitrant in protoplast culture,POD inhi-bitors were stable and kept its inhibitioneffect.Based on all these results,we con-sidered that POD inhibitors might hinderthe biosynthesis of plant cell wall substan-ces catalyzed by POD,hence,the plantcell wall regeneration process of culturedprotoplasts was affected.It might be oneof the reasons that some plant materialswhich were easy for protoplast culture mi-ght exist some unknown mechanisms toscavenge POD inhibitors,hence the pro-cess of cell wall repairing of cultured pro-toplast could get through.