光敏色素互作因子OsPIL15基因对水稻磷、氮吸收利用的影响

Effects of Phytochrome Interacting Factor OsPIL15 gene on Absorption and Utilization of Phosphorus and Nitrogen in Rice

为了分析水稻(Oryza sativa)光敏色素互作因子OsPIL15(Phytochrome interacting factors-like 15)基因调节水稻磷、氮吸收的分子机制,首先利用Transcriptome ENcyclopedia of Rice数据库分析OsPIL15基因对低磷的响应,然后以日本晴和Ospil15突变体为材料,用正常磷(300μmol/L NaH_(2)PO_(4))和低磷(10μmol/L NaH_(2)PO_(4))营养液进行培养,测量水稻幼苗根与地上部生物量及磷、氮含量,并计算磷、氮吸收效率、转运系数及利用率。结果表明,OsPIL15基因响应低磷胁迫,低磷胁迫条件下,Ospil15突变体根和地上部长降幅均小于日本晴;Ospil15突变体地上部干质量降低幅度与日本晴基本一致,但根干质量降低幅度小于日本晴。正常磷条件下,Ospil15突变体根中磷含量显著高于日本晴,而地上部中磷含量与日本晴无显著差异;低磷胁迫条件下,Ospil15突变体根和地上部中磷含量均显著高于日本晴。正常磷和低磷胁迫条件下,Ospil15突变体磷吸收效率均大于日本晴;正常磷条件下,Ospil15突变体磷转运系数小于日本晴,低磷胁迫条件下,磷转运系数大于日本晴。Ospil15突变体对水稻氮吸收亦有影响,Ospil15突变体在正常磷条件下地上部中氮含量显著高于日本晴,而根中氮含量无显著差异;低磷胁迫条件下,根中氮含量显著高于日本晴,而地上部中氮含量没有显著差异。Ospil15突变体在正常磷和低磷胁迫条件下氮吸收效率均高于日本晴,低磷胁迫条件下,氮转运系数小于日本晴,Ospil15突变体在正常磷和低磷胁迫条件下磷、氮利用率均高于日本晴。综上,Ospil15突变体提高了水稻磷、氮吸收和利用,在低磷胁迫条件下,Ospil15突变体提高了磷从根向地上部的转运,抑制了氮从根向地上部的转运,表明OsPIL15基因负调控水稻磷、氮吸收利用。

To analyze the molecular mechanism of rice(Oryza sativa)phytochrome interacting factors-like 15 gene(OsPIL15)regulating rice phosphorus and nitrogen uptake in rice,firstly,the response of OsPIL15 gene to low phosphorus was analyzed by using Transcriptome ENcyclopedia of Rice database,then,Nipponia(Nip)and Ospil15 mutant were cultured under normal phosphorus(300μmol/L NaH_(2)PO_(4))and low phosphorus(10μmol/L NaH_(2)PO_(4))nutrient solution,the root and shoot biomass,phosphorus and nitrogen contents of rice seedlings were measured,and the absorption efficiency,transport coefficient and utilization efficiencies of phosphorus and nitrogen were calculated.The results showed that OsPIL15 responded to low phosphorus stress,the decrease ranges of root and shoot length of Ospil15 mutant were less than those of Nip under low phosphorus condition,and the decrease range of dry shoot weight of Ospil15 mutant was basically the same as that of Nip,but the decrease range of dry root weight of Ospil15 was less than that of Nip.Under normal phosphorus condition,the phosphorus content in root of Ospil15 mutant was significantly higher than that of Nip,but the phosphorus content in shoot of Ospil15 mutant was not significantly different from that of Nip.Under low phosphorus condition,the phosphorus contents in root and shoot of Ospil15 mutant were significantly higher than those of Nip.The phosphorus uptake efficiencies of Ospil15 mutant were higher than those of Nip under normal phosphorus and low phosphorus conditions,the phosphorus transport coefficient of Ospil15 mutant was lower than that of Nip under normal phosphorus condition,and higher than that of Nip under low phosphorus condition.Ospil15 mutant also had an effect on rice nitrogen uptake.Under normal phosphorus condition,the nitrogen content in shoot of Ospil15 mutant was significantly higher than that of Nip,but nitrogen content in root of Ospil15 mutant was not significantly different from Nip.Under low phosphorus condition,the nitrogen content in root was significantly higher than that of Nip,but there was no significant difference in shoot.The nitrogen uptake efficiencies of Ospil15 mutant were higher than those of Nip under normal phosphorus and low phosphorus conditions,and the nitrogen transport coefficient was lower than that of Nip under low phosphorus condition.The phosphorus and nitrogen utilization efficiencies of Ospil15 mutant were higher than those of Nip under both normal and low phosphorus conditions.In summary,the Ospil15 mutant increased the absorption and utilization of phosphorus and nitrogen in rice.Under low phosphorus stress,the OsPIL15 mutant increased the transport of phosphorus from root to shoot,and inhibited the transport of nitrogen from root to shoot.The results showed that OsPIL15 gene negatively regulated the uptake and utilization of phosphorus and nitrogen in rice.