1
|
Abdullah SNA, Ariffin N, Hatta MAM, Kemat N. Opportunity for genome engineering to enhance phosphate homeostasis in crops. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2024; 30:1055-1070. [PMID: 39100872 PMCID: PMC11291846 DOI: 10.1007/s12298-024-01479-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 06/15/2024] [Accepted: 06/24/2024] [Indexed: 08/06/2024]
Abstract
Plants maintain cellular homeostasis of phosphate (Pi) through an integrated response pathway regulated by different families of transcription factors including MYB, WRKY, BHLH, and ZFP. The systemic response to Pi limitation showed the critical role played by inositol pyrophosphate (PP-InsPs) as signaling molecule and SPX (SYG1/PHO81/XPR1) domain proteins as sensor of cellular Pi status. Binding of SPX to PP-InsPs regulates the transcriptional activity of the MYB-CC proteins, phosphate starvation response factors (PHR/PHL) as the central regulator of Pi-deficiency response in plants. Vacuolar phosphate transporter, VPT may sense the cellular Pi status by its SPX domain, and vacuolar sequestration is activated under Pi replete condition and the stored Pi is an important resource to be mobilized under Pi deficiency. Proteomic approaches led to new discoveries of proteins associated with Pi-deficient response pathways and post-translational events that may influence plants in achieving Pi homeostasis. This review provides current understanding on the molecular mechanisms at the transcriptional and translational levels for achieving Pi homeostasis in plants. The potential strategies for employing the CRISPR technology to modify the gene sequences of key regulatory and response proteins for attaining plant Pi homeostasis are discussed.
Collapse
Affiliation(s)
- Siti Nor Akmar Abdullah
- Department of Agriculture Technology, Faculty of Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan Malaysia
- Institute of Plantation Studies (IKP), Universiti Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan Malaysia
| | - Norazrin Ariffin
- Department of Agriculture Technology, Faculty of Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan Malaysia
| | - Muhammad Asyraf Md Hatta
- Department of Agriculture Technology, Faculty of Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan Malaysia
| | - Nurashikin Kemat
- Department of Agriculture Technology, Faculty of Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan Malaysia
| |
Collapse
|
2
|
Liu D, Tan W, Wang H, Li W, Fu J, Li J, Zhou Y, Lin M, Xing W. Genetic diversity and genome-wide association study of 13 agronomic traits in 977 Beta vulgaris L. germplasms. BMC Genomics 2023; 24:413. [PMID: 37488485 PMCID: PMC10364417 DOI: 10.1186/s12864-023-09522-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 07/17/2023] [Indexed: 07/26/2023] Open
Abstract
BACKGROUND Sugar beet (Beta vulgaris L.) is an economically essential sugar crop worldwide. Its agronomic traits are highly diverse and phenotypically plastic, influencing taproot yield and quality. The National Beet Medium-term Gene Bank in China maintains more than 1700 beet germplasms with diverse countries of origin. However, it lacks detailed genetic background associated with morphological variability and diversity. RESULTS Here, a comprehensive genome-wide association study (GWAS) of 13 agronomic traits was conducted in a panel of 977 sugar beet accessions. Almost all phenotypic traits exhibited wide genetic diversity and high coefficient of variation (CV). A total of 170,750 high-quality single-nucleotide polymorphisms (SNPs) were obtained using the genotyping-by-sequencing (GBS). Neighbour-joining phylogenetic analysis, principal component analysis, population structure and kinship showed no obvious relationships among these genotypes based on subgroups or regional sources. GWAS was carried out using a mixed linear model, and 159 significant associations were detected for these traits. Within the 25 kb linkage disequilibrium decay of the associated markers, NRT1/PTR FAMILY 6.3 (BVRB_5g097760); nudix hydrolase 15 (BVRB_8g182070) and TRANSPORT INHIBITOR RESPONSE 1 (BVRB_8g181550); transcription factor MYB77 (BVRB_2g023500); and ethylene-responsive transcription factor ERF014 (BVRB_1g000090) were predicted to be strongly associated with the taproot traits of root groove depth (RGD); root shape (RS); crown size (CS); and flesh colour (FC), respectively. For the aboveground traits, UDP-glycosyltransferase 79B6 (BVRB_9g223780) and NAC domain-containing protein 7 (BVRB_5g097990); F-box protein At1g10780 (BVRB_6g140760); phosphate transporter PHO1 (BVRB_3g048660); F-box protein CPR1 (BVRB_8g181140); and transcription factor MYB77 (BVRB_2g023500) and alcohol acyltransferase 9 (BVRB_2g023460) might be associated with the hypocotyl colour (HC); plant type (PT); petiole length (PL); cotyledon size (C); and fascicled leaf type (FLT) of sugar beet, respectively. AP-2 complex subunit mu (BVRB_5g106130), trihelix transcription factor ASIL2 (BVRB_2g041790) and late embryogenesis abundant protein 18 (BVRB_5g106150) might be involved in pollen quantity (PQ) variation. The candidate genes extensively participated in hormone response, nitrogen and phosphorus transportation, secondary metabolism, fertilization and embryo maturation. CONCLUSIONS The genetic basis of agronomical traits is complicated in heterozygous diploid sugar beet. The putative valuable genes found in this study will help further elucidate the molecular mechanism of each phenotypic trait for beet breeding.
Collapse
Affiliation(s)
- Dali Liu
- National Beet Medium-term Gene Bank, Heilongjiang University, Harbin, 150080, P. R. China
- Key Laboratory of Sugar Beet Genetics and Breeding, College of Advanced Agriculture and Ecological Environment, Heilongjiang University, Harbin, 150080, P. R. China
| | - Wenbo Tan
- National Beet Medium-term Gene Bank, Heilongjiang University, Harbin, 150080, P. R. China
- Key Laboratory of Sugar Beet Genetics and Breeding, College of Advanced Agriculture and Ecological Environment, Heilongjiang University, Harbin, 150080, P. R. China
| | - Hao Wang
- National Beet Medium-term Gene Bank, Heilongjiang University, Harbin, 150080, P. R. China
- Key Laboratory of Sugar Beet Genetics and Breeding, College of Advanced Agriculture and Ecological Environment, Heilongjiang University, Harbin, 150080, P. R. China
| | - Wangsheng Li
- National Beet Medium-term Gene Bank, Heilongjiang University, Harbin, 150080, P. R. China
- Key Laboratory of Sugar Beet Genetics and Breeding, College of Advanced Agriculture and Ecological Environment, Heilongjiang University, Harbin, 150080, P. R. China
| | - Jingjing Fu
- National Beet Medium-term Gene Bank, Heilongjiang University, Harbin, 150080, P. R. China
- Key Laboratory of Sugar Beet Genetics and Breeding, College of Advanced Agriculture and Ecological Environment, Heilongjiang University, Harbin, 150080, P. R. China
| | - Jiajia Li
- National Beet Medium-term Gene Bank, Heilongjiang University, Harbin, 150080, P. R. China
- Key Laboratory of Sugar Beet Genetics and Breeding, College of Advanced Agriculture and Ecological Environment, Heilongjiang University, Harbin, 150080, P. R. China
| | - Yuanhang Zhou
- Xinjiang Academy of Agricultural Sciences, Urumqi, 830091, P. R. China
| | - Ming Lin
- Xinjiang Academy of Agricultural Sciences, Urumqi, 830091, P. R. China
| | - Wang Xing
- National Beet Medium-term Gene Bank, Heilongjiang University, Harbin, 150080, P. R. China.
- Key Laboratory of Sugar Beet Genetics and Breeding, College of Advanced Agriculture and Ecological Environment, Heilongjiang University, Harbin, 150080, P. R. China.
| |
Collapse
|
3
|
Yang M, Sakruaba Y, Ishikawa T, Ohtsuki N, Kawai-Yamada M, Yanagisawa S. Chloroplastic Sec14-like proteins modulate growth and phosphate deficiency responses in Arabidopsis and rice. PLANT PHYSIOLOGY 2023:kiad212. [PMID: 37021761 PMCID: PMC10400038 DOI: 10.1093/plphys/kiad212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 03/09/2023] [Accepted: 04/05/2023] [Indexed: 06/19/2023]
Abstract
Phosphorus is an essential nutrient acquired from soil as phosphate (Pi), and its deficiency severely reduces plant growth and crop yield. Here, we show that single nucleotide polymorphisms (SNPs) at the PHOSPHATIDYLINOSITOL TRANSFER PROTEIN7 (AtPITP7) locus, which encodes a chloroplastic Sec14-like protein, are associated with genetic diversity regarding Pi uptake activity in Arabidopsis (Arabidopsis thaliana). Inactivation of AtPITP7 and its rice (Oryza sativa) homolog (OsPITP6) through T-DNA insertion and CRISPR/Cas9-mediated gene editing, respectively, decreased Pi uptake and plant growth, regardless of Pi availability. By contrast, overexpression of AtPITP7 and OsPITP6 enhanced Pi uptake and plant growth, especially under limited Pi supply. Importantly, overexpression of OsPITP6 increased tiller number and grain yield in rice. Targeted metabolome analysis of glycerolipids in leaves and chloroplasts revealed that inactivation of OsPITP6 alters phospholipid contents, independent of Pi availability, diminishing the reduction in phospholipid content and increase in glycolipid content induced by Pi deficiency; meanwhile, overexpression of OsPITP6 enhanced Pi deficiency induced metabolic alterations. Together with transcriptome analysis of ospitp6 rice plants and phenotypic analysis of grafted Arabidopsis chimeras, these results suggest that chloroplastic Sec14-like proteins play an essential role in growth modulations in response to changes in Pi availability, although their function is critical for plant growth under any Pi condition. The superior traits of OsPITP6-overexpressing rice plants also highlight the potential of OsPITP6 and its homologs in other crops as additional tools for improving Pi uptake and plant growth in low Pi environments.
Collapse
Affiliation(s)
- Mailun Yang
- Agro-Biotechnology Research Center, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Yasuhito Sakruaba
- Agro-Biotechnology Research Center, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Toshiki Ishikawa
- Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
| | - Namie Ohtsuki
- Agro-Biotechnology Research Center, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Maki Kawai-Yamada
- Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
| | - Shuichi Yanagisawa
- Agro-Biotechnology Research Center, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| |
Collapse
|
4
|
Jennings ML. Role of transporters in regulating mammalian intracellular inorganic phosphate. Front Pharmacol 2023; 14:1163442. [PMID: 37063296 PMCID: PMC10097972 DOI: 10.3389/fphar.2023.1163442] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 03/17/2023] [Indexed: 03/31/2023] Open
Abstract
This review summarizes the current understanding of the role of plasma membrane transporters in regulating intracellular inorganic phosphate ([Pi]In) in mammals. Pi influx is mediated by SLC34 and SLC20 Na+-Pi cotransporters. In non-epithelial cells other than erythrocytes, Pi influx via SLC20 transporters PiT1 and/or PiT2 is balanced by efflux through XPR1 (xenotropic and polytropic retrovirus receptor 1). Two new pathways for mammalian Pi transport regulation have been described recently: 1) in the presence of adequate Pi, cells continuously internalize and degrade PiT1. Pi starvation causes recycling of PiT1 from early endosomes to the plasma membrane and thereby increases the capacity for Pi influx; and 2) binding of inositol pyrophosphate InsP8 to the SPX domain of XPR1 increases Pi efflux. InsP8 is degraded by a phosphatase that is strongly inhibited by Pi. Therefore, an increase in [Pi]In decreases InsP8 degradation, increases InsP8 binding to SPX, and increases Pi efflux, completing a feedback loop for [Pi]In homeostasis. Published data on [Pi]In by magnetic resonance spectroscopy indicate that the steady state [Pi]In of skeletal muscle, heart, and brain is normally in the range of 1–5 mM, but it is not yet known whether PiT1 recycling or XPR1 activation by InsP8 contributes to Pi homeostasis in these organs. Data on [Pi]In in cultured cells are variable and suggest that some cells can regulate [Pi] better than others, following a change in [Pi]Ex. More measurements of [Pi]In, influx, and efflux are needed to determine how closely, and how rapidly, mammalian [Pi]In is regulated during either hyper- or hypophosphatemia.
Collapse
|
5
|
Kurita Y, Kanno S, Sugita R, Hirose A, Ohnishi M, Tezuka A, Deguchi A, Ishizaki K, Fukaki H, Baba K, Nagano AJ, Tanoi K, Nakanishi TM, Mimura T. Visualization of phosphorus re-translocation and phosphate transporter expression profiles in a shortened annual cycle system of poplar. PLANT, CELL & ENVIRONMENT 2022; 45:1749-1764. [PMID: 35348214 DOI: 10.1111/pce.14319] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Revised: 02/11/2022] [Accepted: 03/13/2022] [Indexed: 06/14/2023]
Abstract
Phosphorus (P) is an essential macronutrient for plant growth. In deciduous trees, P is remobilized from senescing leaves and stored in perennial tissues during winter for further growth. Annual internal recycling and accumulation of P are considered an important strategy to support the vigorous growth of trees. However, the pathways of seasonal re-translocation of P and the molecular mechanisms of this transport have not been clarified. Here we show the seasonal P re-translocation route visualized using real-time radioisotope imaging and the macro- and micro-autoradiography. We analysed the seasonal re-translocation P in poplar (Populus alba. L) cultivated under 'a shortened annual cycle system', which mimicked seasonal phenology in a laboratory. From growing to senescing season, sink tissues of 32 P and/or 33 P shifted from young leaves and the apex to the lower stem and roots. The radioisotope P re-translocated from a leaf was stored in phloem and xylem parenchyma cells and redistributed to new shoots after dormancy. Seasonal expression profile of phosphate transporters (PHT1, PHT5 and PHO1 family) was obtained in the same system. Our results reveal the seasonal P re-translocation routes at the organ and tissue levels and provide a foothold for elucidating its molecular mechanisms.
Collapse
Affiliation(s)
- Yuko Kurita
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan
- Faculty of Agriculture, Ryukoku University, Shiga, Japan
| | - Satomi Kanno
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan
- The French Alternative Energies and Atomic Energy Commission, Paris, France
| | - Ryohei Sugita
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
- Radioisotope Research Center, Nagoya University, Nagoya, Japan
| | - Atsushi Hirose
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
- School of Pharmacy and Pharmaceutical Sciences, Hoshi University, Tokyo, Japan
| | - Miwa Ohnishi
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan
| | - Ayumi Tezuka
- Faculty of Agriculture, Ryukoku University, Shiga, Japan
| | - Ayumi Deguchi
- Faculty of Agriculture, Ryukoku University, Shiga, Japan
| | - Kimitsune Ishizaki
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan
| | - Hidehiro Fukaki
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan
| | - Kei'ichi Baba
- Research Institute for Sustainable Humanosphere, Kyoto University, Kyoto, Japan
| | - Atsushi J Nagano
- Faculty of Agriculture, Ryukoku University, Shiga, Japan
- Institute for Advanced Biosciences, Keio University, Yamagata, Japan
| | - Keitaro Tanoi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
- JST PRESTO, Kawaguchi, Saitama, Japan
| | - Tomoko M Nakanishi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Tetsuro Mimura
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan
- College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan
| |
Collapse
|
6
|
Gu M, Huang H, Hisano H, Ding G, Huang S, Mitani-Ueno N, Yokosho K, Sato K, Yamaji N, Ma JF. A crucial role for a node-localized transporter, HvSPDT, in loading phosphorus into barley grains. THE NEW PHYTOLOGIST 2022; 234:1249-1261. [PMID: 35218012 DOI: 10.1111/nph.18057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 02/17/2022] [Indexed: 06/14/2023]
Abstract
Grains are the major sink of phosphorus (P) in cereal crops, accounting for 60-85% of total plant P, but the mechanisms underlying P loading into the grains are poorly understood. We functionally characterized a transporter gene required for the distribution of P to the grains in barley (Hordeum vulgare), HvSPDT (SULTR-like phosphorus distribution transporter). HvSPDT encoded a plasma membrane-localized Pi/H+ cotransporter. It was mainly expressed in the nodes at both the vegetative and reproductive stages. Furthermore, its expression was induced by inorganic phosphate (Pi) deficiency. In the nodes, HvSPDT was expressed in both the xylem and phloem region of enlarged and diffuse vascular bundles. Knockout of HvSPDT decreased the distribution of P to new leaves, but increased the distribution to old leaves at the vegetative growth stage under low P supply. However, knockout of HvSPDT did not alter the redistribution of P from old to young organs. At the reproductive stage, knockout of HvSPDT significantly decreased P allocation to the grains, resulting in a considerable reduction in grain yield, especially under P-limited conditions. Our results indicate that node-based HvSPDT plays a crucial role in loading P into barley grains through preferentially distributing P from the xylem and further to the phloem.
Collapse
Affiliation(s)
- Mian Gu
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, 710-0046, Japan
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China
| | - Hengliang Huang
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, 710-0046, Japan
| | - Hiroshi Hisano
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, 710-0046, Japan
| | - Guangda Ding
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, 710-0046, Japan
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
| | - Sheng Huang
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, 710-0046, Japan
| | - Namiki Mitani-Ueno
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, 710-0046, Japan
| | - Kengo Yokosho
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, 710-0046, Japan
| | - Kazuhiro Sato
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, 710-0046, Japan
| | - Naoki Yamaji
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, 710-0046, Japan
| | - Jian Feng Ma
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, 710-0046, Japan
| |
Collapse
|
7
|
Wang Z, Kuo HF, Chiou TJ. Intracellular phosphate sensing and regulation of phosphate transport systems in plants. PLANT PHYSIOLOGY 2021; 187:2043-2055. [PMID: 35235674 PMCID: PMC8644344 DOI: 10.1093/plphys/kiab343] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 06/29/2021] [Indexed: 05/04/2023]
Abstract
Recent research on the regulation of cellular phosphate (Pi) homeostasis in eukaryotes has collectively made substantial advances in elucidating inositol pyrophosphates (PP-InsP) as Pi signaling molecules that are perceived by the SPX (Syg1, Pho81, and Xpr1) domains residing in multiple proteins involved in Pi transport and signaling. The PP-InsP-SPX signaling module is evolutionarily conserved across eukaryotes and has been elaborately adopted in plant Pi transport and signaling systems. In this review, we have integrated these advances with prior established knowledge of Pi and PP-InsP metabolism, intracellular Pi sensing, and transcriptional responses according to the dynamics of cellular Pi status in plants. Anticipated challenges and pending questions as well as prospects are also discussed.
Collapse
Affiliation(s)
- Zhengrui Wang
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan
| | - Hui-Fen Kuo
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan
| | - Tzyy-Jen Chiou
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan
- Author for communication:
| |
Collapse
|
8
|
Chiou TJ. Editorial Feature: Meet the PCP Editor-Tzyy-Jen Chiou. PLANT & CELL PHYSIOLOGY 2021; 62:1357-1358. [PMID: 34405238 DOI: 10.1093/pcp/pcab096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 06/18/2021] [Accepted: 06/26/2021] [Indexed: 06/13/2023]
Affiliation(s)
- Tzyy-Jen Chiou
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei 11529, Taiwan
| |
Collapse
|
9
|
Zhang J, Gu M, Liang R, Shi X, Chen L, Hu X, Wang S, Dai X, Qu H, Li H, Xu G. OsWRKY21 and OsWRKY108 function redundantly to promote phosphate accumulation through maintaining the constitutive expression of OsPHT1;1 under phosphate-replete conditions. THE NEW PHYTOLOGIST 2021; 229:1598-1614. [PMID: 32936937 PMCID: PMC7820984 DOI: 10.1111/nph.16931] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 09/03/2020] [Indexed: 05/20/2023]
Abstract
Plant Phosphate Transporter 1 (PHT1) proteins, probably the only influx transporters for phosphate (Pi) uptake, are partially degraded on sufficient Pi levels to prevent excessive Pi accumulation. Therefore, the basal/constitutive expression level of PHT1 genes is vital for maintaining Pi uptake under Pi-replete conditions. Rice (Oryza sativa) OsPHT1;1 is a unique gene as it is highly expressed and not responsive to Pi, however the mechanism for maintaining its basal/constitutive expression remains unknown. Using biochemical and genetic approaches, we identified and functionally characterised the transcription factors maintaining the basal/constitutive expression of OsPHT1;1. OsWRKY21 and OsWRKY108 interact within the nucleus and both bind to the W-box in the OsPHT1;1 promoter. Overexpression of OsWRKY21 or OsWRKY108 led to increased Pi accumulation, resulting from elevated expression of OsPHT1;1. By contrast, oswrky21 oswrky108 double mutants showed decreased Pi accumulation and OsPHT1;1 expression in a Pi-dependent manner. Moreover, similar to ospht1;1 mutants, plants expressing the OsWRKY21-SRDX fusion protein (a chimeric dominant suppressor) were impaired in Pi accumulation in Pi-replete roots, accompanied by downregulation of OsPHT1;1 expression. Our findings demonstrated that rice WRKY transcription factors function redundantly to promote Pi uptake by activating OsPHT1;1 expression under Pi-replete conditions, and represent a novel pathway independent of the central Pi signalling system.
Collapse
Affiliation(s)
- Jun Zhang
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjing210095China
| | - Mian Gu
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjing210095China
- MOA Key Laboratory of Plant Nutrition and Fertilisation in Lower‐Middle Reaches of the Yangtze RiverNanjing210095China
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource UtilisationNanjing210095China
| | - Ruisuhua Liang
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjing210095China
| | - Xinyu Shi
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjing210095China
| | - Lingling Chen
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjing210095China
| | - Xu Hu
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjing210095China
| | - Shichao Wang
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjing210095China
| | - Xiaoli Dai
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjing210095China
- MOA Key Laboratory of Plant Nutrition and Fertilisation in Lower‐Middle Reaches of the Yangtze RiverNanjing210095China
| | - Hongye Qu
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjing210095China
- MOA Key Laboratory of Plant Nutrition and Fertilisation in Lower‐Middle Reaches of the Yangtze RiverNanjing210095China
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource UtilisationNanjing210095China
| | - Huanhuan Li
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjing210095China
| | - Guohua Xu
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjing210095China
- MOA Key Laboratory of Plant Nutrition and Fertilisation in Lower‐Middle Reaches of the Yangtze RiverNanjing210095China
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource UtilisationNanjing210095China
| |
Collapse
|