【正文】
n et al., 2020)。 然而,AtSPX AtSPX AtSPX4 的 TDNA 嵌入突變體 在 Pi充足或 Pi 不足的條件下沒有出現(xiàn)明顯的表型 變化 (Duan et al., 2020)。在這些方面,在擬南芥中 OsSPX1 的功能類似于 AtSPX3 的功能,僅有一個 SPX域的一類蛋白作為一個負調(diào)控因子是普遍的功能。 闡發(fā) SPX 域蛋白質(zhì)的分子功能重要的一點是其亞細胞定位。因此 SPX 蛋白的定位最有可能由其他誘因或獨聯(lián)體 SPX 域中的域決定的。有趣的是, SHB1–GUS 融合被報在核內(nèi)而不是預(yù)測的跨膜域中 (Kang and Ni, 2020)。不過, SPX 域可以參與 G 蛋白信號轉(zhuǎn)導(dǎo)通路與信息交換表 8 明 SPX 蛋白可以參與信號轉(zhuǎn)導(dǎo)通路。 Chiou et al., 2020。 Sunkar and Zhu, 2020。 Pant et al., 2020) (Figure 1) 。嫁接的實驗已經(jīng)證明 miRNA399可以通過 PHO2轉(zhuǎn)錄成 E2結(jié)合酶的作用 經(jīng)過 篩管從芽轉(zhuǎn)移到根 轉(zhuǎn)運 到根韌 皮部 (Lin et al., 2020。9),并從根吸收 Pi由根轉(zhuǎn)運到芽。除了 miRNA399 和 PHO2,此特定的 Pi 信號系統(tǒng)參與 Pi饑渴 基因 IPS的誘導(dǎo) (Burleigh and Harrison, 1997, 1999。擬南芥中 Pi 饑 渴 的 誘導(dǎo)屬于 IPS基因家 族的 At4基因的變異,導(dǎo)致莖到根 Pi 比率的改變 (Shin et al., 2020)。有趣的是, At3g27150的表達受 Pi 饑餓誘導(dǎo)即使 miR2111 的表達增強。最近出現(xiàn)的全基因組分析技術(shù),通過基因微調(diào) RNA( smRNAs)調(diào)控 列出 基因 的方式 , 參與植物離子穩(wěn)態(tài)的 維持 包括 Pi 的 逐漸增多 (FrancoZorrilla et al., 2020。 miRNA169的目標基因參與的耐旱性與氧化應(yīng)激反應(yīng)調(diào)節(jié) N 和 S缺乏反應(yīng)??傮w而言,全基因組的調(diào)查結(jié)果申明 miRNAs 參與協(xié)調(diào)的 Pi 和不同的營養(yǎng)元素內(nèi)穩(wěn)態(tài)通路,并提出這些途徑和代謝調(diào)節(jié)、 碳同化或氧化脅迫的聯(lián)系 (Hsieh et al., 2020)。最近的研究中發(fā)現(xiàn)兩個 Pi 的轉(zhuǎn)運體 PHT1。 Ciereszko et al., 1996。 Hermans et al., 2020。值得注意的是缺乏 Pi 的植物, 根和芽韌皮部蔗糖 含 量的增加和根表型的變化具有非常密切的聯(lián)系,指示出潛在的 cause–effect 關(guān)系 的 存在 (AlGhazi et al., 2020。外源蔗糖影響基因表達水平導(dǎo)致 Pi 缺乏,如 UDP 葡萄糖磷酸化酶,IPS1, ACP5(編碼酸性磷酸酶)與成員 PHT1 和 PHO1 基因 家族 (Ciereszko et al., 10 2020。 Mu168。 Rubio et al., 2020)。 Martin et al., 2020。 Martin et al., 2020)。 Martin et al., 2020。 Mu168。如生長素和乙烯調(diào)節(jié)下 Pi 的局限性 (Rubio et al., 2020)。 目前 ,這些信號之間的相互關(guān)系的生物學(xué)意義以及它們的分子基礎(chǔ)研究仍然很少的 ,盡管他們對于改善植物對 Pi營養(yǎng)的利用具有很重要的意義。 In Plants Geic Analysis Progress of PiStarvation ABSTRACT Phosphate (Pi) availability is a major factor limiting growth, development, and productivity of plants. In both ecological and agricultural contexts, plants often grow in soils with low soluble phosphate content. Plants respond to this 11 situation by a series of developmental and metabolic adaptations that are aimed at increasing the acquisition of this vital nutrient fromthe soil, as well as to sustain plant growth and survival. The development of a prehensive understanding of how plants sense phosphate deficiency and coordinate the responses via signaling pathways has bee of major interest, and a number of signaling players and works have begun to surface for the regulation of the phosphate deficiency response. In practice, application of such knowledge to improve plant Pi nutrition is hindered by plex crosstalks, which are emerging in the face of new data, such as the coordination of the phosphatedeficiency signaling works with those involved with hormones, photoassimilates (sugar), as well as with the homeostasis of other ions,such as iron. In this review, we focus on these crosstalks and on recent progress in discovering new signaling players involved in the Pistarvation responses, such as proteins having SPX domains. Key words: Phosphate。 phytohormones. 參考文獻: AlGhazi, Y., Muller, B., Pinloche, S., Tranbarger, ., Nacry, P.,Rossignol, M., Tardieu, F., and Doumas, P. (2020). Temporal responses of Arabidopsis root architecture to phosphate starvation: evidence for the involvement of auxin signalling. Plant Cell Environ. 26, 1053–1066. Amtmann, A., Hammond, ., Armengaud, P., and White, . (2020).Nutrient sensing and signalling in plants: potassium and phosphorus. Adv. Bot. Res. 43, 209–257. Auesukaree, C., Homma, T., Kaneko, Y., and Harashima, S. (2020).Transcriptional regulation of phosphateresponsive genes in lowaffinity phosphatetransporterdefective mutants in Saccharomyces cerevisiae. Biochem. Biophys. Res. Com. 306, 843–850. Barabote,.,etal.(2020).Extra domains in secondary transport carriers and channel proteins. Bioch. Biophys. Acta. 1758, 1557–1579. Bari, ., Pant, ., Stitt, M., and Scheible,. (2020). PHO2, micro RNA399 and PHR1 define a phosphate signalling pathway in plants. Plant Physiol. 141, 988–999. Brenner, ., Romanov, ., Kollmer, I., Burkle, L., and Schmulling, T. (2020). Immediateearly and delayed cytokinin response genes of Arabidopsis thaliana identified by genomewide expression profiling reveal novel cytokininsensitive processes and suggest cytokinin action through transcriptional J. 44, 314–333. Burleigh, ., and Harrison, . (1997). A novel gene whose expression in Medicago truncatula roots is suppressed in response to colonization by vesiculararbuscular mycorrhizal (VAM) fungi and to phosphate nutrition. Plant 12 Mol. Biol. 34, 199–208. Burleigh, ., and Harrison, . (1999). The downregulation of Mt4like genes by phosphate fertilization occurs systemically and involves phosphate translocation to the shoots. Plant Physiol. 119, 241–248. CalderonVazquez, C., IbarraLaclette, E., CaballeroPerez, J., and HerreraEstrella, L. (2020). Transcript profiling of Zea mays roots reveals gene responses to phosphate deficiency at the plant and speciesspecific levels. J. Exp. Bot. 59, 2479–2497. Carswell, ., Grant, ., Theodorou, ., Harris, J., Niere, .,and Plaxton, . (1996). The fungicide phosphonate disrupts the phosphatestarvation response in Brassica nigra Physiol. 110, 105–110. Chen, ., Wang, Y., and Wu, . (2020). Membrane transporters for nitrogen, phosphate and potassium uptake in plants. J. Int. Plant Biol. 7, 835–848. Chen, ., Nimmo, ., Jenkins, ., and Nimmo, . (2020). BHLH32 modulates several biochemical and morphological processes that respond to Pi starvation in Arabidopsis. Biochem. , 191–198. Chevalier, F., Pata, M., Nacry, P., Doumas, P., and Rossignol, M. (2020). Effects of phosphate availability on the root system architecture:largescale analysis of the natural variation between Arabidopsis accessions. Plant Cell Environ. 1839–1850. Chiou, . (2020). The role of microRNAs in sensing nutrient Cell Environ. 30, 323–332. Chiou, ., Aung, K., Lin, ., Wu, ., Chiang, ., and Su, . (2020). Regulation of phoshate homeostasis by microRNA in Arabidopsis. Plant