硅对籼稻和粳稻品种磷积累的影响

硅(Si)可以改善磷(P)的营养,但是其内在机制尚不明确。本研究以4个籼稻和3个粳稻品种为研究对象,通过水培试验探究硅对不同水稻品种磷积累的影响。在营养液中添加硅显著降低了籼稻和粳稻品种的地上部磷含量,但几乎不影响根部磷含量。加硅处理不影响所有供试水稻品种的磷吸收及磷从根系向地上部的转移,但提高了磷的利用效率,增加了植株P/Mn和P/Zn比率。磷转运蛋白(PT)基因表达分析表明,在粳稻品种中只有OsPT6被硅下调,而OsPT6在籼稻品种中没有显著性变化;其他PT基因的表达不受硅的影响。由此,硅对不同水稻品种的磷积累有不同的影响,磷利用率的提高可能归因于较高的P/Mn和P/Zn比率,从而导致植物中较高的有效磷。

Effects of Silicon on Phosphorus Accumulation in Different Rice Varieties

Silicon (Si) is able to improve phosphorus (P) nutrition, but the underlying mechanism is still poorly understood. The aim of this study is to investigate the effects of silicon on phosphorus accumulation in different rice varieties including four indica and three japonica accessions in hydroponic solution. Addition of silicon significantly decreased shoot P concentration in both indica and japonica rice varieties, but hardly affected the root P concentration. Si did not affect P uptake, root-to-shoot translocation of P in all rice varieties, but improved P-use efficiency and increased P/Mn and P/Zn in plant. Gene expression analysis of P transporter (PT) genes showed that only OsPT6 was down-regulated by Si in japonica varieties, but not in indica varieties. The expression of other PT genes was unaffected by Si. Taken together, Si has different effect on P accumulation in different rice varieties and improved P-use efficiency is probably attributed to higher P/Mn and P/Zn ratios, resulting in higher P availability in plants.