Peptide transport is important for plant tissues where rapid proteolysis occurs,especially during germination and senescence,to enhance redistribution of organic nitrogen(N).However,the biological role of peptide tran...Peptide transport is important for plant tissues where rapid proteolysis occurs,especially during germination and senescence,to enhance redistribution of organic nitrogen(N).However,the biological role of peptide transporters is poorly investigated in rice.We characterized the function of the peptide transporter OsNPF8.1 of rice nitrate transporter 1/peptide transporter family(NPF).Ectopic expression of OsNPF8.1 in yeast revealed that OsNPF8.1 encoded a high-affinity di-/tri-peptide transporter,and the osnpf8.1 mutants had a lower uptake rate of the fluorescent-labelled dipeptide c in leaves of rice seedlings.Histochemical assays showed that OsNPF8.1 was highly expressed in mesophyll cells and vascular parenchyma cells,but not detected in root hairs and epidermises.Expression of OsNPF8.1 was induced by N deficiency,drought,Na Cl and abscisic acid,and kept at a high level in senescing leaves.Under N deficiency conditions,compared with the wild type Zhonghua 11,the osnpf8.1 mutants grew slower at the seedling stage,and had lower grain yield and lower N content in the grains.In contrast,OsNPF8.1-over-expressing rice(OsNPF8.1-OE)grew faster at the seedling stage and had a higher grain yield.The osnpf8.1 seedlings were less tolerant to salt and drought stresses.These results suggested that stress-induced organic N transportation mediated by OsNPF8.1 might contribute to balance plant growth and tolerate to salt/drought stress and N-deficiency.展开更多
The plant PTR/NRT1(peptide transporter/nitrate transporter 1)gene family com—prises di/tripeptide and low affinity nitrate transporters;some members also recognize other substrates like phytohormones(auxin and abscis...The plant PTR/NRT1(peptide transporter/nitrate transporter 1)gene family com—prises di/tripeptide and low affinity nitrate transporters;some members also recognize other substrates like phytohormones(auxin and abscisic acid)and defence compound glucosinolate.Little is known about members of this gene family in rice(Oryza sativa L.).Here,we report the influence of altered OsPTR9 expression on nitrogen use efficiency,growth and grain yield.OsPTR9 expression is regulated by the exogenous nitrogen source and by the day-night cycle.Elevated expression of OsPTR9 in transgenic rice plants resulted in enhanced ammonium uptake,promotion of lateral root formation,and increased grain yield.On the other hand,downregulation of OsPTR9 in a T-DNA insertion line(osptr9)and in the 0sPTR9一RNAi rice plants had the opposite effect.These results suggest that OsPTR9 may hold potential in improving nitrogen use efficiency and grain yield for rice breeding.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.31772384)Science and Technology Project of Zhanjiang,Guangdong Province,China(Grant No.2021A05030)。
文摘Peptide transport is important for plant tissues where rapid proteolysis occurs,especially during germination and senescence,to enhance redistribution of organic nitrogen(N).However,the biological role of peptide transporters is poorly investigated in rice.We characterized the function of the peptide transporter OsNPF8.1 of rice nitrate transporter 1/peptide transporter family(NPF).Ectopic expression of OsNPF8.1 in yeast revealed that OsNPF8.1 encoded a high-affinity di-/tri-peptide transporter,and the osnpf8.1 mutants had a lower uptake rate of the fluorescent-labelled dipeptide c in leaves of rice seedlings.Histochemical assays showed that OsNPF8.1 was highly expressed in mesophyll cells and vascular parenchyma cells,but not detected in root hairs and epidermises.Expression of OsNPF8.1 was induced by N deficiency,drought,Na Cl and abscisic acid,and kept at a high level in senescing leaves.Under N deficiency conditions,compared with the wild type Zhonghua 11,the osnpf8.1 mutants grew slower at the seedling stage,and had lower grain yield and lower N content in the grains.In contrast,OsNPF8.1-over-expressing rice(OsNPF8.1-OE)grew faster at the seedling stage and had a higher grain yield.The osnpf8.1 seedlings were less tolerant to salt and drought stresses.These results suggested that stress-induced organic N transportation mediated by OsNPF8.1 might contribute to balance plant growth and tolerate to salt/drought stress and N-deficiency.
文摘The plant PTR/NRT1(peptide transporter/nitrate transporter 1)gene family com—prises di/tripeptide and low affinity nitrate transporters;some members also recognize other substrates like phytohormones(auxin and abscisic acid)and defence compound glucosinolate.Little is known about members of this gene family in rice(Oryza sativa L.).Here,we report the influence of altered OsPTR9 expression on nitrogen use efficiency,growth and grain yield.OsPTR9 expression is regulated by the exogenous nitrogen source and by the day-night cycle.Elevated expression of OsPTR9 in transgenic rice plants resulted in enhanced ammonium uptake,promotion of lateral root formation,and increased grain yield.On the other hand,downregulation of OsPTR9 in a T-DNA insertion line(osptr9)and in the 0sPTR9一RNAi rice plants had the opposite effect.These results suggest that OsPTR9 may hold potential in improving nitrogen use efficiency and grain yield for rice breeding.
