Oross J W, Thomson W W
Eur J Cell Biol. 1982 Oct;28(2):257-63.
The salt glands of Bermuda grass were found to be similar to those of many dicotyledonous plants with respect to the relatively large quantities of chloride that accumulate in the subcuticular collecting chamber of secreting glands. The salt glands of grasses lack the suberized or cuticularized zone that is present in the walls of the glands of dicotyledonous plants that has been hypothesized to prevent the apoplastic backflow of accumulated salts from the collecting chamber to the leaf mesophyll. An ionic lanthanum solution was used to determine whether or not the apoplastic pathway is blocked between the collecting chamber and the leaf mesophyll. The results of the lanthanum tracer study revealed that this pathway is significantly restricted. It was determined that the restriction of the apoplastic pathway was due to the highly lignified condition of the lateral cell walls in the outer portion of the basal gland cell. The lanthanum tracer study also revealed that an apoplastic continuum exists between the leaf mesophyll and a system of membranous extracellular channels that occur in the basal cell. Based on this finding, it was suggested that the extracellular channels may function in the absorption of solutes from the apoplast.
人们发现，狗牙根的盐腺与许多双子叶植物的盐腺相似，其分泌腺的皮下收集腔中积累了相对大量的氯离子。草类植物的盐腺缺乏双子叶植物盐腺壁中存在的栓质化或角质化区域，据推测该区域可防止积累的盐分从收集腔通过质外体回流到叶肉。使用离子镧溶液来确定质外体途径在收集腔和叶肉之间是否被阻断。镧示踪研究的结果表明，该途径受到显著限制。已确定质外体途径的限制是由于基部腺细胞外部的外侧细胞壁高度木质化。镧示踪研究还表明，叶肉与基部细胞中存在的膜状细胞外通道系统之间存在质外体连续体。基于这一发现，有人提出细胞外通道可能在从质外体吸收溶质中发挥作用。
