In traditional opinions, no radial transportation was considered to occur in the bamboo internodes but was usually considered to occur in the nodes. Few studies involved the phloem unloading and post-phloem transport pathways in the rapid elongating bamboo shoots. Our observations indicated a symplastic pathway in phloem unloading and post-unloading pathways in the culms of Fargesia yunnanensis, based on 5,6-carboxyfluorescein diacetate tracing experiment. Significant lignification and suberinization in fiber and parenchyma cell walls in maturing internodes, blocked the apoplastic transport. Assimilates were transported out of the vascular bundles in four directions in the inner zones but in two directions in the outer zones via the continuum of parenchyma cells. In transverse sections, assimilates were outward transported from the inner zones to the outer zones. Assimilates transport velocities varied with time, with the highest values at 0:00 a.m., which were affected by water transport. The assimilate transport from the the adult culms to the young shoots also varied with the developmental degrees of bamboo shoots, with the highest transport velocities in the rapidly elongating internodes. The localization of sucrose, glucose, starch grains and the related enzymes reconfirmed that the parenchyma cells in and around the vascular bundles constituted a symplastic pathway for the radial transport of sugars and were the main sites for sugar metabolism. The parenchyma cells functioned as the "rays" for the radial transport in and between vascular bundles in bamboo internodes. These results systematically revealed the transport mechanism of assimilate and water in the elongating bamboo shoots.

中文翻译：

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竹节间伸长过程中同韧韧皮部的卸载和韧皮部后的运输。

传统观点认为，在竹节间不发生径向运输，但通常认为在节间发生径向运输。很少有研究涉及快速伸长的竹笋中韧皮部的卸载和韧皮部后的运输途径。根据5,6-羧基荧光素二乙酸酯示踪实验，我们的观察结果表明云南Fargesia茎部韧皮部卸载和卸载后的共生途径。成熟的节间中纤维和薄壁组织细胞壁中明显的木质化和亚硒化作用阻止了质外性运输。通过实质细胞的连续体，同化物在内部区域中沿四个方向从血管束中运出，而在外部区域中沿两个方向运出。在横截面中 同化物从内部区域向外运输到外部区域。同化运输速度随时间而变化，最高值为0:00 am，受水运输影响。从成年茎到幼嫩芽的同化运输也随竹笋的发育程度而变化，在快速伸长的节间中具有最高的运输速度。蔗糖，葡萄糖，淀粉颗粒和相关酶的定位再次证实，血管束内和周围的薄壁细胞构成了糖径向运输的共生途径，并且是糖代谢的主要部位。实质细胞充当“射线”，用于在竹节间的血管束内和血管束之间进行径向运输。