Inhibition of Lectin Agglutination with Pseudomonas solanacearum by Carbohydrates

Abstract

Agglutination of Pseudomonas solamacearum cells by tomato lectins in inhibited by three carbohydrates. Glucosamine hydrochloride and D-glucouronic acid inhibit agglutination of the virulent P. solanacearum (#64) by lectins isolated from VC-8 (resistant) or C-28 (susceptible) tomato lines left uninoculated or inoculated with virulent or avirulent isolates of the pathogen. Agglutination of the avirulent isolate (#64-β) of the bacterium by these lectins is inhibited by addition of D-glucouronic acid and methyl-D-mannoside. The carbohydrate, D-glucouronic acid, generally inhibits agglutination of P. solanacearum cells by lectins from resistant and susceptible tomato lines whereas agglutination inhibition by glucosamine hydrochloride and methyl-D-mannosides is variable depending on the lectin source, the isolates used for inoculation, and the isolates used for to determine agglutination titer. 試驗結果顯示，三種碳水化合物包括氯氫葡醣醛醯胺(Glucosamine hydrochloride)，D-葡糖醛酸(D-glucouronic acid)及甲基甘露糖苷(Methyl-D-mannoside)可抑制番茄聚血素(lectins)與青枯病菌之凝集現象(agglutination)的發生。利用有毒性(virulent)或無毒性(avirulent)之青枯病菌菌株接種番茄抗病品系(VC-8)或罹病品系(C-28)所產生的聚血素來測定它與青枯病菌的凝集現象，發現這種聚血素與青枯病菌菌株(#64)之凝集現象會受氯氫葡糖醛醯胺及D-葡糖醛酸的抑制。不同的，聚血素與無毒性的菌株(#64-β)之凝集現象，則受D-葡糖醛酸與甲基甘露糖苷的抑制。綜合所有的資料得知不論是從抗病品系或罹病品系所獲得之聚血素，其與青枯病菌之凝集現象，均可為D-葡糖醛酸所抑制。相反的，氯氫葡糖醛醯胺與甲基甘露糖苷對凝集現象的抑制，則會受聚血素來源、接種菌株及凝集濃度值的不同而有所差異。