Transcriptome and Metabolome Analysis Provide Insights into Root and Root Released Organic Anion Responses to Phosphorus Deficiency in Oat

First author: Yanliang Wang; Affiliations: Norwegian Institute of Bioeconomy Research (挪威生物经济研究所): Akershus, Norway

Corresponding author: Jihong Liu-Clarke

Root and root-released organic anions (有机阴离子) play important roles in uptake of phosphorus (P; 磷), an essential macronutrient (大量营养元素) for food production. Oat (燕麦), ranking sixth in the world's cereal production, contains valuable nutritional compounds and can withstand (承受) poor soil conditions. Our aim was to investigate root transcriptional and metabolic responses of oat grown under P-deficient and P-sufficient conditions. We conducted a hydroponic experiment (水培试验) and measured root morphology and organic anion exudation (分泌), and analysed changes in the transcriptome and metabolome. Oat roots showed enhanced citrate (柠檬酸盐) and malate (苹果酸盐) exudation after four weeks of P deficiency. After 10 days of P deficiency, we identified 9371 differentially expressed transcripts with a two-fold or greater change (p < 0.05): forty-eight sequences predicted to be involved in organic anion biosynthesis and efflux were consistently up-regulated; twenty-four up-regulated transcripts in oat were also found up-regulated upon P starvation in rice and wheat under similar conditions. Phosphorylated metabolites (i.e. glucose-6-phosphate 葡萄糖-6-磷酸, myo-inositol-phosphate 肌醇磷酸) were reduced dramatically, while citrate and malate, some sugars and amino acids increased slightly in P-deficient oat roots. Our data are consistent with a strategy of increased organic anion efflux and a shift in primary metabolism in response to P deficiency in oat.

根和根释放的有机阴离子在植物吸收对于食物产量非常重要的大量营养元素P的过程中扮演重要的作用。燕麦，世界排名第六的谷类作物，富含营养复合物，能够在贫瘠的土地上种植。作者的目标是研究燕麦在P缺少和P富足时根的转录和代谢响应。作者进行了一个水培试验，并测量了根的形态和有机阴离子分泌，分析转录与代谢的改变。研究显示，燕麦的P缺失条件下培养第4周之后开始明显增加柠檬酸盐和苹果酸盐的分泌。在P缺失10天之后，作者鉴定到了9371个至少两倍差异表达的转录本，其中58个上调表达转录本被预测参与了有机阴离子的生物合成和外流，而24个上调表达的转录本在水稻和小麦类似条件P缺失处理下的表达趋势一致。在P缺失的燕麦根中，葡萄糖-6-磷酸和肌醇磷酸等磷酸化代谢物剧烈减少，而柠檬酸盐、苹果酸盐以及一些糖类和氨基酸的含量有所增加。本文的研究证实了燕麦在P缺失时表现出了增加有机阴离子外流和一些主要代谢产物变化的响应策略。

通讯：Jihong Liu-Clarke (http://www.bioforsk.no/ikbViewer/page/en/person?p_document_id=6255)

个人简介：1979-1983年，吉林农业大学，农学学士；1983-1986年，四川农业大学，遗传学硕士；1997-2003年，挪威大学，病理与分子生物学博士。

doi: https://doi.org/10.1093/jxb/ery176

Journal: Journal of Experimental Botany

Published date: 11 May, 2018

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