Nogueira Ravena Malheiros, Bragança Gracielle Pimenta Pereira, Picoli Edgard Augusto de Toledo, de Oliveira Denis Coelho, Isaias Rosy Mary Dos Santos
Department of Botany, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Department of Plant Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil.
Front Plant Sci. 2025 Jan 30;16:1507552. doi: 10.3389/fpls.2025.1507552. eCollection 2025.
Hemipteran gall vascular traits result from the access, piercing, and sucking of the inducer mouth parts directly in the xylem and phloem conductive cells. Herein, our focus relies on mapping the features of phloem cells in the proximal, median, and distal regions of stem galls and adjacent galled stems.
Phloem cells were dissociated from gall fragments, the stem portions above and below the galls, and the proximal and distal regions of stem galls. were measured. The comparison of the higher length and diameter of the sieve tube elements (STE) was evaluated considering the priority of nutrient flow to gall portions.
In the system, there were no significant differences in the dimensions of the STE in the galls compared with those of the stem portions above and below the galls.
At the cytological level, the callose deposited in gall STE and the decrease in the cell lumen area in the stem portion above the gall due to thickened nacreous cell walls have implications for nutrient flow. Peculiarly, the smaller sieve pores in the sieve plates of the STE located in the galls and stem portions above and below them and the deposition of P-protein in the stem portions below the galls limit the bidirectional transport of nutrients, benefiting the transport of photoassimilates to the gall proximal region and reducing the vigor of apple tree stems.
半翅目昆虫形成的虫瘿的维管特征是由诱导者的口器直接在木质部和韧皮部的传导细胞中取食、穿刺和吸食所导致的。在此，我们的重点是描绘茎虫瘿及其相邻受害茎干的近端、中部和远端区域韧皮部细胞的特征。
从虫瘿碎片、虫瘿上方和下方的茎段以及茎虫瘿的近端和远端区域分离出韧皮部细胞并进行测量。考虑到养分向虫瘿部分流动的优先级，评估筛管分子（STE）较高的长度和直径的比较情况。
在该系统中，与虫瘿上方和下方的茎段相比，虫瘿中筛管分子的尺寸没有显著差异。
在细胞学水平上，虫瘿筛管分子中胼胝质的沉积以及虫瘿上方茎段中由于珠母质细胞壁增厚导致细胞腔面积减小对养分流动有影响。特别地，位于虫瘿及其上方和下方茎段中的筛管分子筛板上较小的筛孔以及虫瘿下方茎段中P蛋白的沉积限制了养分的双向运输，有利于光合产物向虫瘿近端区域的运输，并降低苹果树茎干的活力。
