A method for simultaneously monitoring phloem and xylem reconnections in grafted watermelon seedlings
A method for simultaneously monitoring phloem and xylem reconnections in grafted watermelon seedlings
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DOI：
10.1101/2021.08.07.455541
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发表时间：
2021-08
期刊：
影响因子：
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通讯作者：
Jianuo Xu;Xiaoyang Wei;Mu Xiong;Ting Zhang;Changjin Liu;Z. Bie;Yuan Huang
中科院分区：
文献类型：
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作者：
Jianuo Xu;Xiaoyang Wei;Mu Xiong;Ting Zhang;Changjin Liu;Z. Bie;Yuan Huang
嫁接是提高西瓜对生物和非生物胁迫耐性的有效途径。然而，嫁接苗的成活在很大程度上取决于嫁接的成功形成。因此，了解移植物的形成过程，特别是血管重联过程是至关重要的。本研究发现，西瓜茎中的木质素在蓝光激发下表现出较强的自体荧光，这使得5(6)-羧基荧光素二乙酸酯(CFDA)等蓝光激发荧光示踪剂不适合用于测定西瓜维管连通性。相比之下，紫外光激发的秦皮甲素和红光激发的酸性品红分别被证明是监测自嫁接西瓜韧皮部和木质部连通性的有效FTS。此外，在接穗的子叶和砧木的根上联合应用七叶皂苷和酸性品红，可以同时监测个别自嫁接西瓜幼苗的韧皮部和木质部的连通性。此外，该方法也适用于甜瓜和黄瓜自嫁接的韧皮部和木质部再连接以及西瓜、甜瓜和黄瓜在南瓜砧木上的异种嫁接。根据建立的方法，我们发现自嫁接西瓜韧皮部和木质部的重联没有及时分离。此外，低温和去根子叶都延缓了西瓜维管连接的进程。综上所述，该方法不仅为分析西瓜的维管连通性提供了一种方便、准确、快速的方法，也为其他葫芦科作物的维管连通性分析提供了一种方便、准确、快速的方法。
Grafting is an effective way to increase watermelon tolerance to biotic and abiotic stresses. However, the survival of grafted seedlings largely depends on successful graft formation. Therefore, understanding the graft formation process, particularly the vascular reconnection process is of critical importance. This study found that lignin in watermelon stem shows strong auto-fluorescence under blue-light excitation which makes blue-light excited fluorescent tracers (FTs) such as 5(6)-carboxy fluorescein diacetate (CFDA) become unsuitable for assaying vascular connectivity in watermelon. In contrast, UV-light excited esculin and red-light excited acid fuchsin were proved to be efficient FTs for monitoring the phloem and xylem connectivity, respectively, in self-grafted watermelon. Furthermore, a combined application of esculin to the scion cotyledon and acid fuchsin to the rootstock root enabled simultaneous monitoring of the phloem and xylem connectivity in individual self-grafted watermelon seedlings. In addition, this method is also applicable in investigating the phloem and xylem reconnections in self-grafted melon and cucumber, and heterograft of watermelon, melon and cucumber onto pumpkin rootstock. Based on this established method, we found that phloem and xylem reconnections are not timely separated in self-grafted watermelon. Furthermore, low temperature and removal of the rootstock cotyledons both delayed the vascular reconnection process in watermelon. In conclusion, this new method provides a convenient, accurate and rapid way to analyze the vascular connectivity not only in watermelon, but also in other cucurbit crops.