Abstract

結(jié)果：N deficiency significantly decreased N content, dry weight, chlorophyll (Chl) content, L-theanine and the activities of N metabolism-related enzymes, but increased the content of total flavonoids and polyphenols in tea leaves. N deficiency delayed the sprouting time of tea buds. By using the RNA-seq technique and subsequent bioinformatics analysis, 3050 up-regulated and 2688 down-regulated differentially expressed genes (DEGs) were isolated in tea leaves in response to N deficiency. However, only 1025 genes were up-regulated and 744 down-regulated in roots. Gene ontology (GO) term enrichment analysis showed that 205 DEGs in tea leaves were enriched in seven GO terms and 152 DEGs in tea roots were enriched in 11 GO items based on P < 0.05. In tea leaves, most GO-enriched DEGs were involved in chlorophyll a/b binding activities, photosynthetic performance, and transport activities. But most of the DEGs in tea roots were involved in the metabolism of carbohydrates and plant hormones with regard to the GO terms of biological processes. N deficiency significantly increased the expression level of phosphate transporter genes, which indicated that N deficiency might impair phosphorus metabolism in tea leaves. Furthermore, some DEGs, such as probable anion transporter 3 and high-affinity nitrate transporter 2.7, might be of great potential in improving the tolerance of N deficiency in tea plants and further study could work on this area in the future.

結(jié)論：Our results indicated N deficiency inhibited the growth of tea plant, which might be due to altered N metabolism and expression levels of DEGs involved in the photosynthetic performance, transport activity and oxidation–reduction processes..

代表圖片

中文摘要

背景

作為一種重要的經(jīng)濟(jì)作物，茶葉對(duì)氮的依賴(lài)性很強(qiáng)。然而，茶樹(shù)中氮缺乏反應(yīng)的生理和分子機(jī)制尚未完全了解。將茶樹(shù)品種“春綠2”用含有0 mM[N-缺乏]或3 mM（對(duì)照）NH4NO3的營(yíng)養(yǎng)液在含有干凈河沙的6 L陶罐中培養(yǎng)。

結(jié)果

缺氮顯著降低了茶葉中N含量、干重、葉綠素（Chl）含量、L-茶氨酸和N代謝相關(guān)酶的活性，但增加了茶葉中總黃酮和多酚的含量。缺氮延緩了茶芽的萌發(fā)時(shí)間。通過(guò)使用RNA-seq技術(shù)和隨后的生物信息學(xué)分析，在茶樹(shù)葉片中分離到3050個(gè)上調(diào)和2688個(gè)下調(diào)的差異表達(dá)基因（DEG）。然而，根中只有1025個(gè)基因表達(dá)上調(diào)，744個(gè)基因表達(dá)下調(diào)。GO富集分析表明，茶葉中205個(gè)DEG在7個(gè)GO術(shù)語(yǔ)中富集，茶葉根中152個(gè)DEG富集在11個(gè)GO項(xiàng)目中。在茶葉中，大多數(shù)富含GO的DEG參與葉綠素a/b結(jié)合活性、光合性能和運(yùn)輸活性。但根中的大多數(shù)DEG都與碳水化合物和植物激素的代謝有關(guān)。缺氮顯著增加了磷酸鹽轉(zhuǎn)運(yùn)蛋白基因的表達(dá)水平，這表明缺氮可能會(huì)影響茶葉的磷代謝。此外，一些DEG，如可能的陰離子轉(zhuǎn)運(yùn)蛋白3和高親和力硝酸鹽轉(zhuǎn)運(yùn)蛋白2.7，可能在提高茶樹(shù)對(duì)氮缺乏的耐受性方面具有巨大潛力，未來(lái)可以在這方面開(kāi)展進(jìn)一步的研究。

結(jié)論：

我們的結(jié)果表明，氮缺乏抑制了茶樹(shù)的生長(zhǎng)，這可能是由于氮代謝和參與光合性能、運(yùn)輸活性和氧化還原過(guò)程的DEG的表達(dá)水平發(fā)生了變化。