Vascular bundle

Boucheron-Dubuisson E, Bayle V, Bonke M; et al. Diarch symmetry of the vascular bundle in Arabidopsis root encompasses the pericycle and is reflected in distich

送。同时，叶的水分也需要维管束内的木质部从根部等吸收水分和无机盐的器官运输、供应到其它部位。致密薄壁组织所组成的维管束鞘（英语：Vascular bundle#Bundle-sheath cells）以及厚角組織可以保护维管束，并支撑叶片，使之能伸展接受阳光。观察叶片表面，可以发现叶脉的走向在单子叶植物和双子叶植物是有所区别的。

proteins: affibody binding proteins developed from a small three-helix bundle scaffold. FEBS J. June 2008, 275 (11): 2668–76. PMID 18435759. doi:10.1111/j

PMID 10869053. doi:10.1093/brain/123.7.1410 .  Schmahmann, Jeremy D. Vascular Syndromes of the Thalamus. Stroke. 2003-09-21, 34 (9): 2264–2278 [2024-01-21]

Shi, S; Klein, O; Sharpe, P; Chai, Y. Secretion of shh by a neurovascular bundle niche supports mesenchymal stem cell homeostasis in the adult mouse incisor