西南林业大学学报2025，Vol.45Issue(5)：7-18,12.DOI:10.11929/j.swfu.202405033
低磷胁迫下杉木根系对硝态氮的响应
Response of Cunninghamia lanceolata Roots to Nitrate Nitrogen Addition Under Phosphorus Starvation
摘要
Abstract
A controlled hydroponic experiment was conducted utilizing seedlings from various half-sibling families of Cunninghamia lanceolata as research subjects.Following treatments involving regular phosphorus supply and low phosphorus stress for 15 days,the seedlings were further cultivated for an additional 15 days un-der 4 levels of nitrogen supply(0.5×,1×,1.5×,and 2×)across both phosphorus conditions.The changes in root morphology,root secretion,protective enzyme activity,nitrogen metabolism related enzyme activity,and nitro-gen and phosphorus metabolism related gene expression of C.lanceolata seedlings under normal phosphorus sup-ply and low phosphorus stress were analyzed.This study aims to elucidate the adaptive mechanisms of C.lanceol-ata seedling roots in response to varying intensities of nitrate nitrogen application under the specified phosphorus conditions.It was found that the root morphological response of C.lanceolata family 10 was the most sensitive,and the high intensity nitrate treatment under low phosphorus stress significantly promoted root proliferation and lateral root growth.The addition of nitrate nitrogen could significantly alleviate the decrease of phosphorus con-tent in roots of family 10 due to phosphorus deficiency stress and significantly increase the secretion of acid phos-phatase and organic acids in roots.The activities of superoxide dismutase,catalase and peroxidase,and the con-tent of malondialdehyde in roots decreased significantly.In addition,nitrate nitrogen addition could not effect-ively alleviate the weakening of nitrogen metabolism activity caused by low phosphorus stress.Under low phos-phorus stress,nitrate reductase(NR)activity and nitrite reductase(NiR)activity decreased significantly in family 10,while NR and NiR activities in roots of nitrate nitrogen treatment were still lower than those of normal phos-phorus treatment.The results of quantitative PCR analysis showed that the addition of nitrate nitrogen under nor-mal phosphorus supply could significantly down-regulate the expression of ClNRT1.1,ClNIR1 and ClCPR2 to re-duce nitrogen uptake and metabolism,while under low phosphorus stress,nitrate nitrogen addition could signific-antly up-regulate the expression of ClNIR1 and ClCPR2 to increase the ability of nitrate nitrogen reduction,thus improving the ability to adapt to high nitrogen and low phosphorus environment.关键词
杉木/硝态氮/低磷胁迫/根系/氮磷协同Key words
Cunninghamia lanceolata/nitrate nitrogen/low phosphorus stress/root response/phosphorus-ni-trogen分类
农业科技引用本文复制引用
陈海姝,陈婉婷,林雅雯,赵铭臻,李明..低磷胁迫下杉木根系对硝态氮的响应[J].西南林业大学学报,2025,45(5):7-18,12.基金项目
福建省自然科学基金项目(2022J01122)资助. （2022J01122）
