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Zhang Y, Hu Y, Wang Z, Lin X, Li Z, Ren Y, Zhao J. The translocase of the inner mitochondrial membrane 22-2 is required for mitochondrial membrane function during Arabidopsis seed development. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:4427-4448. [PMID: 37105529 DOI: 10.1093/jxb/erad141] [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: 09/26/2022] [Accepted: 04/27/2023] [Indexed: 06/19/2023]
Abstract
The carrier translocase (also known as translocase of the inner membrane 22; TIM22 complex) is an important component of the mitochondrial protein import apparatus. However, the biological functions of AtTIM22-2 in Arabidopsis remain poorly defined. Here, we report studies on two tim22-2 mutants that exhibit defects in embryo and endosperm development, leading to seed abortion. AtTIM22-2, which was localized in mitochondria, was widely expressed in embryos and in various seedling organs. Loss of AtTIM22-2 function resulted in irregular mitochondrial cristae, decreased respiratory activity, and a lower membrane potential, together with changes in gene expression and enzyme activity related to reactive oxygen species (ROS) metabolism, leading to increased accumulation of ROS in the embryo. The levels of transcripts encoding mitochondrial protein import components were also altered in the tim22-2 mutants. Furthermore, mass spectrometry, bimolecular fluorescence complementation and co-immunoprecipitation assays revealed that AtTIM22-2 interacted with AtTIM23-2, AtB14.7 (a member of Arabidopsis OEP16 family encoded by At2G42210), and AT5G27395 (mitochondrial inner membrane translocase complex, subunit TIM44-related protein). Taken together, these results demonstrate that AtTIM22-2 is essential for maintaining mitochondrial membrane functions during seed development. These findings lay the foundations for a new model of the composition and functions of the TIM22 complex in higher plants.
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Affiliation(s)
- Yuqin Zhang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yuanyuan Hu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Zhiqin Wang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Xiaodi Lin
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Zihui Li
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yafang Ren
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Jie Zhao
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
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2
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Ghifari AS, Saha S, Murcha MW. The biogenesis and regulation of the plant oxidative phosphorylation system. PLANT PHYSIOLOGY 2023; 192:728-747. [PMID: 36806687 DOI: 10.1093/plphys/kiad108] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 01/19/2023] [Accepted: 01/22/2023] [Indexed: 06/01/2023]
Abstract
Mitochondria are central organelles for respiration in plants. At the heart of this process is oxidative phosphorylation (OXPHOS) system, which generates ATP required for cellular energetic needs. OXPHOS complexes comprise of multiple subunits that originated from both mitochondrial and nuclear genome, which requires careful orchestration of expression, translation, import, and assembly. Constant exposure to reactive oxygen species due to redox activity also renders OXPHOS subunits to be more prone to oxidative damage, which requires coordination of disassembly and degradation. In this review, we highlight the composition, assembly, and activity of OXPHOS complexes in plants based on recent biochemical and structural studies. We also discuss how plants regulate the biogenesis and turnover of OXPHOS subunits and the importance of OXPHOS in overall plant respiration. Further studies in determining the regulation of biogenesis and activity of OXPHOS will advances the field, especially in understanding plant respiration and its role to plant growth and development.
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Affiliation(s)
- Abi S Ghifari
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA 6009, Australia
| | - Saurabh Saha
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA 6009, Australia
| | - Monika W Murcha
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA 6009, Australia
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3
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Zhong F, Ke W, Li Y, Chen X, Zhou T, Xu B, Qi L, Yan Z, Ma Y. Comprehensive analysis of the complete mitochondrial genomes of three Coptis species ( C. chinensis, C. deltoidea and C. omeiensis): the important medicinal plants in China. FRONTIERS IN PLANT SCIENCE 2023; 14:1166420. [PMID: 37313257 PMCID: PMC10258346 DOI: 10.3389/fpls.2023.1166420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 04/11/2023] [Indexed: 06/15/2023]
Abstract
Coptis plants (Ranunculaceae) contain high levels of isoquinoline alkaloids and have a long history of medicinal use. Coptis species are of great value in pharmaceutical industries and scientific research. Mitochondria are considered as one of the central units for receiving stress signals and arranging immediate responses. Comprehensive characterizations of plant mitogenomes are imperative for revealing the relationship between mitochondria, elucidating biological functions of mitochondria and understanding the environmental adaptation mechanisms of plants. Here, the mitochondrial genomes of C. chinensis, C. deltoidea and C. omeiensis were assembled through the Nanopore and Illumina sequencing platform for the first time. The genome organization, gene number, RNA editing sites, repeat sequences, gene migration from chloroplast to mitochondria were compared. The mitogenomes of C. chinensis, C. deltoidea and C. omeiensis have six, two, two circular-mapping molecules with the total length of 1,425,403 bp, 1,520,338 bp and 1,152,812 bp, respectively. The complete mitogenomes harbors 68-86 predicted functional genes including 39-51 PCGs, 26-35 tRNAs and 2-5 rRNAs. C. deltoidea mitogenome host the most abundant repeat sequences, while C. chinensis mitogenome has the largest number of transferred fragments from its chloroplasts. The large repeat sequences and foreign sequences in the mitochondrial genomes of Coptis species were related to substantial rearrangements, changes in relative position of genes and multiple copy genes. Further comparative analysis illustrated that the PCGs under selected pressure in mitochondrial genomes of the three Coptis species mainly belong to the mitochondrial complex I (NADH dehydrogenase). Heat stress adversely affected the mitochondrial complex I and V, antioxidant enzyme system, ROS accumulation and ATP production of the three Coptis species. The activation of antioxidant enzymes, increase of T-AOC and maintenance of low ROS accumulation in C. chinensis under heat stress were suggested as the factors for its thermal acclimation and normal growth at lower altitudes. This study provides comprehensive information on the Coptis mitogenomes and is of great importance to elucidate the mitochondrial functions, understand the different thermal acclimation mechanisms of Coptis plants, and breed heat-tolerant varieties.
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Affiliation(s)
- Furong Zhong
- State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Wenjia Ke
- State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Yirou Li
- State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Xiaoyan Chen
- State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Tao Zhou
- State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Binjie Xu
- Innovative institute of Chinese Medicine and Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Luming Qi
- School of Health Preservation and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
- Key Laboratory of Traditional Chinese Medicine Regimen and Health, State Administration of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Zhuyun Yan
- State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Yuntong Ma
- State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
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Wang Y, Shi D, Zhu H, Yin H, Wang G, Yang A, Song Z, Jing Q, Shuai B, Xu N, Yang J, Chen H, Wang G. Revisiting maize Brittle endosperm-2 reveals new insights in BETL development and starchy endosperm filling. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2023; 332:111727. [PMID: 37149228 DOI: 10.1016/j.plantsci.2023.111727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 03/18/2023] [Accepted: 05/03/2023] [Indexed: 05/08/2023]
Abstract
Rerouting the starch biosynthesis pathway in maize can generate specialty types, like sweet corn and waxy corn, with a drastically increasing global demand. Hence, a fine-tuning of starch metabolism is relevant to create diverse maize cultivars for end-use applications. Here, we characterized a new maize brittle endosperm mutant, referred to as bt1774, which exhibited decreased starch content but a dramatic increase of soluble sugars at maturity. Both endosperm and embryo development was impaired in bt1774 relative to the wild-type (WT), with a prominently arrested basal endosperm transfer layer (BETL). Map-based cloning revealed that BRITTLE ENDOSPERM2 (Bt2), which encodes a small subunit of ADP-glucose pyrophosphorylase (AGPase), is the causal gene for bt1774. A MuA2 element was found to be inserted into intron 2 of Bt2, leading to a severe decrease of its expression, in bt1774. This is in line with the irregular and loosely packed starch granules in the mutant. Transcriptome of endosperm at grain filling stage identified 1, 013 differentially expressed genes in bt1774, which were notably enriched in the BETL compartment, including ZmMRP1, Miniature1, MEG1, and BETLs. Gene expression of the canonical starch biosynthesis pathway was marginally disturbed in Bt1774. Combined with the residual 60% of starch in this nearly null mutant of Bt2, this data strongly suggests that an AGPase-independent pathway compensates for starch synthesis in the endosperm. Consistent with the BETL defects, zein accumulation was impaired in bt1774. Co-expression network analysis revealed that Bt2 probably has a role in intracellular signal transduction, besides starch synthesis. Altogether, we propose that Bt2 is likely involved in carbohydrate flux and balance, thus regulating both the BETL development and the starchy endosperm filling.
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Affiliation(s)
- Yongyan Wang
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT-China (Henan) Joint Center of Wheat and Maize, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450002, China
| | - Dongsheng Shi
- School of Environmental and Rural Science, University of New England, Armidale, New South Wales, Australia
| | - Hui Zhu
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT-China (Henan) Joint Center of Wheat and Maize, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450002, China
| | - Hanxue Yin
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT-China (Henan) Joint Center of Wheat and Maize, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450002, China
| | - Gaoyang Wang
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT-China (Henan) Joint Center of Wheat and Maize, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450002, China
| | - Anqi Yang
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT-China (Henan) Joint Center of Wheat and Maize, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450002, China
| | - Zhixuan Song
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT-China (Henan) Joint Center of Wheat and Maize, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450002, China
| | - Qingquan Jing
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT-China (Henan) Joint Center of Wheat and Maize, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450002, China
| | - Bilian Shuai
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Ningkun Xu
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT-China (Henan) Joint Center of Wheat and Maize, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450002, China
| | - Jianping Yang
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT-China (Henan) Joint Center of Wheat and Maize, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450002, China
| | - Hongyu Chen
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT-China (Henan) Joint Center of Wheat and Maize, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450002, China.
| | - Guifeng Wang
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT-China (Henan) Joint Center of Wheat and Maize, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450002, China.
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Zhou Q, Fu Z, Li M, Shen Q, Sun C, Feng Y, Liu Y, Jiang J, Qin T, Mao T, Hearne SJ, Wang G, Tang J. Maize tubulin folding cofactor B is required for cell division and cell growth through modulating microtubule homeostasis. THE NEW PHYTOLOGIST 2023. [PMID: 36843261 DOI: 10.1111/nph.18839] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 02/20/2023] [Indexed: 06/18/2023]
Abstract
Tubulin folding cofactors (TFCs) are required for tubulin folding, α/β tubulin heterodimer formation, and microtubule (MT) dynamics in yeast and mammals. However, the functions of their plant counterparts remain to be characterized. We identified a natural maize crumpled kernel mutant, crk2, which exhibits reductions in endosperm cell number and size, as well as embryo/seedling lethality. Map-based cloning and functional complementation confirmed that ZmTFCB is causal for the mutation. ZmTFCB is targeted mainly to the cytosol. It facilitates α-tubulin folding and heterodimer formation through sequential interactions with the cytosolic chaperonin-containing TCP-1 ε subunit ZmCCT5 and ZmTFCE, thus affecting the organization of both the spindle and phragmoplast MT array and the cortical MT polymerization and array formation, which consequently mediated cell division and cell growth. We detected a physical association between ZmTFCB and the maize MT plus-end binding protein END-BINDING1 (ZmEB1), indicating that ZmTFCB1 may modulate MT dynamics by sequestering ZmEB1. Our data demonstrate that ZmTFCB is required for cell division and cell growth through modulating MT homeostasis, an evolutionarily conserved machinery with some species-specific divergence.
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Affiliation(s)
- Qingqian Zhou
- National Key Laboratory of Wheat and Maize Crops Science/Collaborative Innovation Center of Henan Grain Crops/College of Agronomy, Henan Agricultural University, Zhengzhou, 450046, China
| | - Zhiyuan Fu
- National Key Laboratory of Wheat and Maize Crops Science/Collaborative Innovation Center of Henan Grain Crops/College of Agronomy, Henan Agricultural University, Zhengzhou, 450046, China
| | - Mengyuan Li
- National Key Laboratory of Wheat and Maize Crops Science/Collaborative Innovation Center of Henan Grain Crops/College of Agronomy, Henan Agricultural University, Zhengzhou, 450046, China
| | - Qingwen Shen
- National Key Laboratory of Wheat and Maize Crops Science/Collaborative Innovation Center of Henan Grain Crops/College of Agronomy, Henan Agricultural University, Zhengzhou, 450046, China
| | - Canran Sun
- National Key Laboratory of Wheat and Maize Crops Science/Collaborative Innovation Center of Henan Grain Crops/College of Agronomy, Henan Agricultural University, Zhengzhou, 450046, China
| | - Yijian Feng
- National Key Laboratory of Wheat and Maize Crops Science/Collaborative Innovation Center of Henan Grain Crops/College of Agronomy, Henan Agricultural University, Zhengzhou, 450046, China
| | - Yang Liu
- National Key Laboratory of Wheat and Maize Crops Science/Collaborative Innovation Center of Henan Grain Crops/College of Agronomy, Henan Agricultural University, Zhengzhou, 450046, China
| | - Jianjun Jiang
- National Key Laboratory of Wheat and Maize Crops Science/Collaborative Innovation Center of Henan Grain Crops/College of Agronomy, Henan Agricultural University, Zhengzhou, 450046, China
| | - Tao Qin
- College of Grassland Agriculture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Tonglin Mao
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Sarah Jane Hearne
- CIMMYT, KM 45 Carretera Mexico-Veracruz, El Batan, Texcoco, Estado de México, 56237, Mexico
| | - Guifeng Wang
- National Key Laboratory of Wheat and Maize Crops Science/Collaborative Innovation Center of Henan Grain Crops/College of Agronomy, Henan Agricultural University, Zhengzhou, 450046, China
| | - Jihua Tang
- National Key Laboratory of Wheat and Maize Crops Science/Collaborative Innovation Center of Henan Grain Crops/College of Agronomy, Henan Agricultural University, Zhengzhou, 450046, China
- The Shennong Laboratory, Zhengzhou, Henan, 450002, China
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