Silicon (Si) has beneficial effects in a variety of plant species and environments. Soil and climate affect silica accumulation in given plant species, but their roles on foliar silicification patterns and balance between silica and C-rich biopolymers as structural components is poorly known. We studied silica deposition in situ in sugarcane leaves collected in three tropical environments differing in soil and climate. Plant silica deposits were physically extracted from leaves through wet digestion. Leaves were observed and mapped for Si by ESEM-EDX. The C-rich biopolymers in leaves were determined by the Van Soest method. Silicon accumulation in the leaves was related to bioavailable Si in soil and plant transpiration. Epidermal silica deposits were either limited to silica cells as dumbbell-shaped phytoliths, or expanded to long and short cells arranged in prominent veins fully silicified, depending on whether the leaf Si concentration was lowest or highest. The size of silica deposits increased with increasing leaf Si through an increasing number of conjoined silicified cells. Leaf ash-free cellulose and Si concentrations were negatively correlated. Soil and climate impact markedly the magnitude of foliar silicification, with possibly significant impact on mechanical properties and Si-related plant functions. Environmental conditions further impact the counterbalance between silica and cellulose as leaf structural components via different levels of Si accumulation.

中文翻译：

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土壤和气候影响甘蔗 (Saccharum officinarum) 的叶片硅化模式和二氧化硅-纤维素平衡

硅 (Si) 在多种植物物种和环境中具有有益作用。土壤和气候影响给定植物物种中二氧化硅的积累，但它们对叶硅化模式的作用以及作为结构组分的二氧化硅和富含碳的生物聚合物之间的平衡知之甚少。我们研究了在土壤和气候不同的三种热带环境中收集的甘蔗叶中二氧化硅的原位沉积。通过湿消化从叶子中物理提取植物二氧化硅沉积物。通过 ESEM-EDX 观察叶子并绘制 Si。叶子中富含 C 的生物聚合物通过 Van Soest 方法测定。叶片中硅的积累与土壤中的生物可利用硅和植物蒸腾作用有关。表皮二氧化硅沉积物要么限于作为哑铃形植硅体的二氧化硅细胞，或扩展到排列在突出叶脉中的长短细胞完全硅化，这取决于叶硅浓度是最低还是最高。二氧化硅沉积物的大小随着叶片 Si 的增加而增加，通过连接的硅化细胞数量增加。叶无灰纤维素与Si浓度呈负相关。土壤和气候显着影响叶面硅化的程度，可能对机械特性和与硅相关的植物功能产生重大影响。环境条件通过不同水平的 Si 积累进一步影响作为叶片结构成分的二氧化硅和纤维素之间的平衡。二氧化硅沉积物的大小随着叶片 Si 的增加而增加，通过连接的硅化细胞数量增加。叶无灰纤维素与Si浓度呈负相关。土壤和气候显着影响叶面硅化的程度，可能对机械特性和与硅相关的植物功能产生重大影响。环境条件通过不同水平的 Si 积累进一步影响作为叶片结构成分的二氧化硅和纤维素之间的平衡。二氧化硅沉积物的大小随着叶片 Si 的增加而增加，通过连接的硅化细胞数量增加。叶无灰纤维素与Si浓度呈负相关。土壤和气候显着影响叶面硅化的程度，可能对机械特性和与硅相关的植物功能产生重大影响。环境条件通过不同水平的 Si 积累进一步影响作为叶片结构成分的二氧化硅和纤维素之间的平衡。