Evidence for graft transmission of structural phloem proteins or their precursors in heterografts of Cucurbitaceae
Evidence for graft transmission of structural phloem proteins or their precursors in heterografts of Cucurbitaceae
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DOI：
10.1007/s004250050441
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发表时间：
1998-11-01
期刊：
影响因子：
4.3
通讯作者：
Kollmann, R
中科院分区：
文献类型：
--
作者：
Golecki, B;Schulz, A;Kollmann, R
以葫芦科植物种间和属间嫁接为材料，研究了结构P蛋白在韧皮部中的移动性。黄瓜（Cucumis sativus L.）将接穗嫁接到南瓜砧木上，嫁接后9-11 d，接穗分泌物的十二烷基硫酸钠-聚丙烯酰胺电泳凝胶上至少出现了9种额外的蛋白质。这些蛋白质完全对应的，各自的南瓜属物种的砧木，包括形成粘性的韧皮部蛋白质PPI和韧皮部凝集素PP 2，所示的表观分子量和肽图谱。根据三个位点的探测，额外的蛋白质均匀地分布在接穗中。额外的蛋白质的外观与整个嫁接联合韧皮部桥的建立相关。发育的巧合表明，结构蛋白或其前体在韧皮部中发生了转移。这种易位是葫芦科中的普遍现象，如通过比较筛选所示：在11个嫁接组合中，使用冬瓜（Benincasa hispida（Thunb.）Cogn.，西瓜Citrullus colocynthis（L.）施拉德，Cucumis梅洛L.、C. sativus，Cucurbita ficifolia Bouche，Cucurbita maxima Duchesne ex Lam.，和瓜形天花粉Trichosanthes cucumerina var.野牡丹根据该筛选，额外蛋白质的传递方向取决于测试的组合。虽然一些移植物伴侣未能显示交换，但一些表现为额外蛋白质的“供体”，还有一些可能既是“供体”又是“受体”。然而，无论是作为接穗还是砧木，C. sativus一直被鉴定为受体。发生额外的蛋白质在异嫁接讨论方面的运输机制的结构P-蛋白质在韧皮部和同化物运输的关系。
Interspecific and intergeneric grafts of Cucurbitaceae were used to study the mobility of structural P-proteins in the phloem. When Cucumis sativus L. scions were grafted onto Cucurbita rootstocks, at least nine additional proteins appeared on sodium dodecyl sulfate-polyacrylamide electrophoresis gels of scion exudate, 9-11 d after grafting. These proteins corresponded exactly to those of the, respective Cucurbita sp. rootstock, including the filament-forming phloem protein PPI and the phloem lectin PP2, as shown by the apparent molecular weights and peptide maps. According to probing at three sites, the additional proteins were evenly distributed within the scion. The appearance of additional proteins was correlated with the establishment of phloem bridges across the graft union. The developmental coincidence establishes that the structural proteins or their precursors are translocated in the phloem. This translocation was a universal phenomenon in Cucurbitaceae as shown by a comparative screening: for additional proteins in eleven graft combinations, using Benincasa hispida (Thunb.) Cogn., Citrullus colocynthis (L.) Schrad., Cucumis melo L, C. sativus, Cucurbita ficifolia Bouche, Cucurbita maxima Duchesne ex Lam., and Trichosanthes cucumerina var. lobata Roxb. According to this screening, the direction of transmission of additional proteins depended upon the combination tested. While some graft partners failed to show exchange, some behaved as "donor" for additional proteins and still others could be both "donor" or "acceptor". However, whether used as scion or stock, C. sativus was consistently identified as an acceptor. The occurrence of additional proteins in heterografts is discussed with regard to the transport mechanism of structural P-proteins in the phloem and its relationship to assimilate transport.