Key message

The origin of xylem cells, intracellular variation, and gall position relative to the host plant organ are related to mechanisms that positively compensate hydraulic conductivity in galls.

Abstract

Gall position in its host organ may be determinant for the new patterns of xylem differentiation. Leaf galls may be attached to the host leaf by a peduncle, as the extralaminar galls, or may develop in a morphological continuum with their host organ, as the intralaminar galls. Due to these two distinct positions and the related patterns of cell differentiation, gall vascular cells and tissues may vary in area and size, which were investigated in the structural features of the vessel elements in galls and in their connections with their host leaflets in three gall morphotypes associated to Inga ingoides. Also, as phytohormones orchestrate the differentiation of vascular cells, the sites of accumulation of auxins and cytokinins were detected by histochemical techniques. Besides aspects of cell differentiation, cytometric and histometric xylem features, as well as the relative water content were evaluated looking for compensatory mechanisms related to hydraulic status of the galls and the gall constriction hypothesis. The detection of auxins was related with the differentiation of new vascular cells. The origin of xylem cells, intracellular variation, and gall position relative to the host plant organ are related to mechanisms that positively compensate the hydraulic conductivity in galls. Extralaminar galls develop as appendages of adventitious origin, which theoretically imply in rupture with the host leaf ontogenetical pattern. Based on the fact that gall position influences xylem cell features, the gall-constriction hypothesis was revisited with leaflet galls as models of study, but was corroborated just for the intralaminar galls.

中文翻译：

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胆汁位置对Inga ingoides（Rich。）Willd小叶木质部特征的影响。（豆科：Ca科）

关键信息

木质部细胞的起源，细胞内变异以及相对于宿主植物器官的胆位置与积极补偿胆中水力传导性的机制有关。

抽象

胆汁在其宿主器官中的位置可能决定木质部分化的新模式。gall虫可以通过花序梗附着在寄主叶片上，如层外gall虫，也可以像其内部器官那样在形态连续体中发育，如层内intra虫。由于这两个不同的位置以及相关的细胞分化模式，胆囊血管细胞和组织的面积和大小可能会有所不同，这在胆囊中血管元件的结构特征以及与它们在三个胆囊中与宿主小叶的连接方面进行了研究与Inga ingoides相关的形态型。另外，由于植物激素协调血管细胞的分化，因此通过组织化学技术检测了生长素和细胞分裂素的蓄积位点。除了细胞分化方面，还评估了细胞计数和组织计量的木质部特征以及相对含水量，以寻找与胆汁水力状态和胆囊收缩假说相关的补偿机制。生长素的检测与新血管细胞的分化有关。木质部细胞的起源，细胞内变异以及相对于宿主植物器官的胆位置与积极补偿胆中水力传导性的机制有关。层外胆虫是不定起源的附属物，在理论上暗示宿主叶片的个体发育模式破裂。