蔗糖对柱花草根尖类边缘细胞形成及耐铝功能的影响

Effects of sucrose on the formation of root border-like cells and aluminum tolerance in Stylosanthes guianensis

【目的】根尖边缘细胞在植物对生物与非生物胁迫适应中起重要作用,但其形成的生理机制仍需进一步探究。本研究旨在探究蔗糖对柱花草Stylosanthes guianensis根尖类边缘细胞的形成及其铝毒耐受能力的影响。【方法】以圭亚那柱花草‘热研2号’为试验材料,采用外源添加糖源的方法,分析柱花草根尖类边缘细胞的形态特征,研究蔗糖对柱花草幼苗耐铝能力的影响。【结果】蔗糖和葡萄糖均能明显促进柱花草根尖类边缘细胞的形成。添加蔗糖处理的根尖类边缘细胞鲜质量、长度和宽度与无糖处理相比分别增加50%、14%和62%,细胞层数增加3~4层。保留根尖类边缘细胞的柱花草具有较强的耐铝能力;与无糖处理相比,蔗糖处理后形成的根尖类边缘细胞具有更强的吸铝能力,根尖铝累积明显减少,根系相对生长速率增加45%。【结论】蔗糖可以促进柱花草根尖类边缘细胞的形成,增强铝处理下根尖类边缘细胞对柱花草的保护作用。本研究结果为进一步探究柱花草根尖类边缘细胞发育及其适应铝毒胁迫的机制提供了理论依据。

【Objective】Root border cells(BCs)play important roles in plant resistance to biotic and abiotic stresses.However,the physiological mechanisms of BCs formation remains further exploration.This study was aimed to investigate the effects of sucrose on root border-like cells(BLCs)formation and aluminum(Al)tolerance function of stylo(Stylosanthes guianensis).【Method】Genotype‘Reyan No.2’was used as plant material,exogenous carbohydrate sources were applied in the growth medium for treatments,and the morphology of stylo BLCs and the stylo Al tolerance were investigated.【Result】Both sucrose and glucose obviously promoted stylo BLCs formation.Compared with sugar-free,sucrose increased the fresh weight,length and width of stylo BLCs by 50%,14%and 62%respectively,and the number of cell layers was also higher as indicated by 3−4 layers more.The stylo retaining BLCs had strong aluminum resistance.Moreover,compared with sugar-free control,BLCs induced by sucrose showed stronger Al absorption ability,this subsequently enhanced the stylo Al resistance as indicated by the lower root tip Al accumulation and higher root relative growth rate,which increased by 45%.【Conclusion】Sucrose can promote BLCs formation in stylo,and subsequently enhance the stylo Al resistance.These results expand the knowledge on the development of BLCs and their function in stylo Al resistance.