1
|
Shi C, Wang D, Guan Y, Qu H. Dissection and ultramicroscopic observation of an apical pollen tube of Pyrus. PLANT REPRODUCTION 2022; 35:1-8. [PMID: 34731307 DOI: 10.1007/s00497-021-00433-0] [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: 08/13/2019] [Accepted: 10/25/2021] [Indexed: 06/13/2023]
Abstract
The pollen tube is ideal for studying cell polar growth, and observing the ultrastructure of the pollen tube tip using transmission electron microscopy (TEM) is the primary method for studying pollen tube growth. The preparation of ultrathin sections of the pollen tube tip sample is important for its successful microscopic observation. The direction of pollen tube growth in vitro is irregular, and it is difficult to dissect the tip of the pollen tube during ultrathin sectioning. Here, we used two methods to efficiently obtain an ultrathin section of the pollen tube tip of Pyrus. In the first method, laser micro-cutting was used to obtain the pollen tube tip, followed by ultrathin sectioning. In the other method, the pollen tubes were cultured in the same growth direction, followed by ultrathin sectioning. Ultrathin sections, which were observed via TEM, showed typical characteristics of the pollen tube tip, such as dense vesicles, numerous mitochondria, and secretory vesicles of the Golgi. We concluded that these two methods are effective in pollen tube tip sample preparation for ultrathin sectioning and provide the foundation for observing the ultrastructure of pollen tube tips.
Collapse
Affiliation(s)
- Chenxi Shi
- College of Horticulture, Qingdao Agricultural University, No. 700 Changcheng Road, Qingdao City, 266109, Shandong Province, China
| | - Demian Wang
- College of Horticulture, Qingdao Agricultural University, No. 700 Changcheng Road, Qingdao City, 266109, Shandong Province, China
| | - Yaqin Guan
- College of Horticulture, Qingdao Agricultural University, No. 700 Changcheng Road, Qingdao City, 266109, Shandong Province, China
| | - Haiyong Qu
- College of Horticulture, Qingdao Agricultural University, No. 700 Changcheng Road, Qingdao City, 266109, Shandong Province, China.
| |
Collapse
|
2
|
Qiu L, Wang Y, Qu H. Loading calcium fluorescent probes into protoplasts to detect calcium in the flesh tissue cells of Malus domestica. HORTICULTURE RESEARCH 2020; 7:91. [PMID: 32528703 PMCID: PMC7261807 DOI: 10.1038/s41438-020-0315-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 03/03/2020] [Accepted: 03/20/2020] [Indexed: 05/23/2023]
Abstract
Cytosolic Ca2+ plays a key role in signal transduction in plants. Calcium imaging is the most common approach to studying dynamic changes in the cytoplasmic Ca2+ content. Here, we used mature 'Fuji' apples (Malus pumila Mill.) to obtain viable protoplasts from flesh tissue cells by enzymatic hydrolysis; then, three small-molecule fluorescent probes (fluo-8/AM, fluo-4/AM, and rhod-2/AM) were loaded into the protoplasts. All three Ca2+ fluorescent probes successfully entered the cytoplasm but did not enter the vacuole. Both the Ca2+ chelator (EGTA) and Ca2+ channel blocker (La3+) reduced the fluorescence intensity in the cytoplasm. The calcium ionophore A23187 increased the fluorescence intensity in the cytoplasm at 5 µmol/L but decreased it at 50 µmol/L. Additionally, A23187 reversed the fluorescence intensity in the cytoplasm, which was decreased by La3+. Ionomycin is also a calcium ionophore that can increase the fluorescence intensity of calcium in the cytoplasm. These results suggest that small-molecule Ca2+ fluorescent probes can be used to detect changes in cytosolic calcium levels in the cells of fruit flesh tissue. In addition, the optimum concentration of fluo-8/AM was determined to be 5 µmol/L. This was the first time that protoplasts have been isolated from apple flesh tissue cells and small-molecule fluorescent probes have been used to detect calcium in the cytoplasm of flesh tissue cells. This study provides a new method to study calcium signal transduction in fruit flesh tissue.
Collapse
Affiliation(s)
- Lina Qiu
- College of Horticulture, Qingdao Agricultural University, Qingdao City, China
| | - Yongzhang Wang
- College of Horticulture, Qingdao Agricultural University, Qingdao City, China
| | - Haiyong Qu
- College of Horticulture, Qingdao Agricultural University, Qingdao City, China
| |
Collapse
|
3
|
Shi D, Wu J, Tang H, Yin H, Wang H, Wang R, Wang R, Qian M, Wu J, Qi K, Xie Z, Wang Z, Zhao X, Zhang S. Single-pollen-cell sequencing for gamete-based phased diploid genome assembly in plants. Genome Res 2019; 29:1889-1899. [PMID: 31649061 PMCID: PMC6836740 DOI: 10.1101/gr.251033.119] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Accepted: 10/01/2019] [Indexed: 11/30/2022]
Abstract
Genome assemblies from diploid organisms create mosaic sequences alternating between parental alleles, which can create erroneous gene models and other problems. In animals, a popular strategy to generate haploid genome-resolved assemblies has been the sampling of (haploid) gametes, and the advent of single-cell sequencing has further advanced such methods. However, several challenges for the isolation and amplification of DNA from plant gametes have limited such approaches in plants. Here, we combined a new approach for pollen protoplast isolation with a single-cell DNA amplification technique and then used a “barcoding” bioinformatics strategy to incorporate haploid-specific sequence data from 12 pollen cells, ultimately enabling the efficient and accurate phasing of the pear genome into its A and B haploid genomes. Beyond revealing that 8.12% of the genes in the pear reference genome feature mosaic assemblies and enabling a previously impossible analysis of allelic affects in pear gene expression, our new haploid genome assemblies provide high-resolution information about recombination during meiosis in pollen. Considering that outcrossing pear is an angiosperm species featuring very high heterozygosity, our method for rapidly phasing genome assemblies is potentially applicable to several yet-unsequenced outcrossing angiosperm species in nature.
Collapse
Affiliation(s)
- Dongqing Shi
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Jun Wu
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Haibao Tang
- Center for Genomics and Biotechnology, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian Province, China
| | - Hao Yin
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Hongtao Wang
- School of Life Science, Henan University, Kaifeng 475004, China
| | - Ran Wang
- College of Agriculture, Qingdao Agricultural University, Qingdao 266109, China
| | - Runze Wang
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Ming Qian
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Juyou Wu
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Kaijie Qi
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Zhihua Xie
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | | | | | - Shaoling Zhang
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| |
Collapse
|
4
|
Zhang J, Zhang D, Wei J, Shi X, Ding H, Qiu S, Guo J, Li D, Zhu K, Horvath DP, Xia Y. Annual growth cycle observation, hybridization and forcing culture for improving the ornamental application of Paeonia lactiflora Pall. in the low-latitude regions. PLoS One 2019; 14:e0218164. [PMID: 31194806 PMCID: PMC6564672 DOI: 10.1371/journal.pone.0218164] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 05/28/2019] [Indexed: 11/19/2022] Open
Abstract
Expanding the southern range of herbaceous peony (Paeonia lactiflora Pall.) is a meaningful and worthwhile horticultural endeavor in the Northern Hemisphere. However, high temperatures in winter seriously hinder the bud dormancy release and flowering of peony in the more southern areas of subtropical and tropical regions. Resource introduction and hybridization can contribute to creating new cultivars with high adaptability in a warmer winter climate. In this study, three representative cultivars of P. lactiflora were screened for flowering capabilities and their annual growth cycles were observed to provide information needed for hybridization. Among these three cultivars, ‘Hang Baishao’ is the best adapted cultivar for southern growing regions and is unique in its ability to thrive in southern areas of N 30°00’. Pollen viability of ‘Hang Baishao’ was 55.60% based on five measuring methods, which makes it an excellent male parent in hybridization. Hybrid plants among these three cultivars grew well, but all of their flower buds aborted. Additionally, the ability of three growth regulators that advance the flowering of ‘Hang Baishao’ to promote an indoor cultivation strategy for improving peony application as a potted or cut-flower plant was tested. 5-azacytidine could impact the growth of ‘Hang Baishao’ and induce dwarfism and small flowers but not advance the flowering time. Gibberellin A3 promoted the sprouting and growth significantly, but all plants eventually withered. Chilling at 0–4°C for four weeks and irrigation with 300 mg/L humic acid was the optimal combination used to hasten flowering and ensure flowering quality simultaneously. These results can lay the foundation for future studies on the chilling requirement trait, bud dormancy release and key functional gene exploration of herbaceous peony. Additionally, this study can also provide guidance for expanding the range of economically important plants with the winter dormancy trait to the low-latitude regions.
Collapse
Affiliation(s)
- Jiaping Zhang
- Physiology and Molecular Biology Laboratory of Ornamental Plants, Institute of Landscape Architecture, College of Agriculture & Biotechnology, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Dong Zhang
- Physiology and Molecular Biology Laboratory of Ornamental Plants, Institute of Landscape Architecture, College of Agriculture & Biotechnology, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Jianfen Wei
- Research & Development Center, Hangzhou Landscaping Incorporated, Hangzhou, Zhejiang Province, China
| | - Xiaohua Shi
- Research & Development Centre of Flower, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang Province, China
| | - Huaqiao Ding
- Research & Development Centre of Flower, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang Province, China
| | - Shuai Qiu
- Research & Development Center, Hangzhou Landscaping Incorporated, Hangzhou, Zhejiang Province, China
| | - Juan Guo
- Research & Development Center, Hangzhou Landscaping Incorporated, Hangzhou, Zhejiang Province, China
| | - Danqin Li
- Physiology and Molecular Biology Laboratory of Ornamental Plants, Institute of Landscape Architecture, College of Agriculture & Biotechnology, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Kaiyuan Zhu
- Research & Development Centre of Flower, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang Province, China
| | - David P. Horvath
- Sunflower and Plant Biology Research, Red River Valley Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, Fargo, North Dakota, United States of America
- * E-mail: (YX); (DH)
| | - Yiping Xia
- Physiology and Molecular Biology Laboratory of Ornamental Plants, Institute of Landscape Architecture, College of Agriculture & Biotechnology, Zhejiang University, Hangzhou, Zhejiang Province, China
- * E-mail: (YX); (DH)
| |
Collapse
|
5
|
Scheible N, McCubbin A. Signaling in Pollen Tube Growth: Beyond the Tip of the Polarity Iceberg. PLANTS (BASEL, SWITZERLAND) 2019; 8:E156. [PMID: 31181594 PMCID: PMC6630365 DOI: 10.3390/plants8060156] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/04/2019] [Accepted: 06/06/2019] [Indexed: 12/15/2022]
Abstract
The coordinated growth of pollen tubes through floral tissues to deliver the sperm cells to the egg and facilitate fertilization is a highly regulated process critical to the Angiosperm life cycle. Studies suggest that the concerted action of a variety of signaling pathways underlies the rapid polarized tip growth exhibited by pollen tubes. Ca2+ and small GTPase-mediated pathways have emerged as major players in the regulation of pollen tube growth. Evidence suggests that these two signaling pathways not only integrate with one another but also with a variety of other important signaling events. As we continue to elucidate the mechanisms involved in pollen tube growth, there is a growing importance in taking a holistic approach to studying these pathways in order to truly understand how tip growth in pollen tubes is orchestrated and maintained. This review considers our current state of knowledge of Ca2+-mediated and GTPase signaling pathways in pollen tubes, how they may intersect with one another, and other signaling pathways involved. There will be a particular focus on recent reports that have extended our understanding in these areas.
Collapse
Affiliation(s)
- Nolan Scheible
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA.
| | - Andrew McCubbin
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA.
- Center for Reproductive Biology, Pullman, WA, 99164, USA.
| |
Collapse
|
6
|
Laggoun F, Dardelle F, Dehors J, Falconet D, Driouich A, Rochais C, Dallemagne P, Lehner A, Mollet JC. A chemical screen identifies two novel small compounds that alter Arabidopsis thaliana pollen tube growth. BMC PLANT BIOLOGY 2019; 19:152. [PMID: 31010418 PMCID: PMC6475968 DOI: 10.1186/s12870-019-1743-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 03/27/2019] [Indexed: 05/23/2023]
Abstract
BACKGROUND During sexual reproduction, pollen grains land on the stigma, rehydrate and produce pollen tubes that grow through the female transmitting-tract tissue allowing the delivery of the two sperm cells to the ovule and the production of healthy seeds. Because pollen tubes are single cells that expand by tip-polarized growth, they represent a good model to study the growth dynamics, cell wall deposition and intracellular machineries. Aiming to understand this complex machinery, we used a low throughput chemical screen approach in order to isolate new tip-growth disruptors. The effect of a chemical inhibitor of monogalactosyldiacylglycerol synthases, galvestine-1, was also investigated. The present work further characterizes their effects on the tip-growth and intracellular dynamics of pollen tubes. RESULTS Two small compounds among 258 were isolated based on their abilities to perturb pollen tube growth. They were found to disrupt in vitro pollen tube growth of tobacco, tomato and Arabidopsis thaliana. We show that these 3 compounds induced abnormal phenotypes (bulging and/or enlarged pollen tubes) and reduced pollen tube length in a dose dependent manner. Pollen germination was significantly reduced after treatment with the two compounds isolated from the screen. They also affected cell wall material deposition in pollen tubes. The compounds decreased anion superoxide accumulation, disorganized actin filaments and RIC4 dynamics suggesting that they may affect vesicular trafficking at the pollen tube tip. CONCLUSION These molecules may alter directly or indirectly ROP1 activity, a key regulator of pollen tube growth and vesicular trafficking and therefore represent good tools to further study cellular dynamics during polarized-cell growth.
Collapse
Affiliation(s)
- Ferdousse Laggoun
- Normandie Université, UNIROUEN, Laboratoire Glycobiologie et Matrice Extracellulaire Végétale EA4358, Fédération de Recherche “NORVEGE”- FED 4277, 76000 Rouen, France
| | - Flavien Dardelle
- Normandie Université, UNIROUEN, Laboratoire Glycobiologie et Matrice Extracellulaire Végétale EA4358, Fédération de Recherche “NORVEGE”- FED 4277, 76000 Rouen, France
- Present Address: LPS-BioSciences, Bâtiment 409, Université Paris-Sud, 91400 Orsay, France
| | - Jérémy Dehors
- Normandie Université, UNIROUEN, Laboratoire Glycobiologie et Matrice Extracellulaire Végétale EA4358, Fédération de Recherche “NORVEGE”- FED 4277, 76000 Rouen, France
| | - Denis Falconet
- Laboratoire de Physiologie Cellulaire et Végétale, CNRS, CEA, INRA, Université Grenoble Alpes, Institut de Biosciences et Biotechnologies de Grenoble, CEA Grenoble, 38000 Grenoble, cedex 9 France
| | - Azeddine Driouich
- Normandie Université, UNIROUEN, Laboratoire Glycobiologie et Matrice Extracellulaire Végétale EA4358, Fédération de Recherche “NORVEGE”- FED 4277, 76000 Rouen, France
| | - Christophe Rochais
- Normandie Université, UNICAEN, Centre d’Etudes et de Recherche sur le Médicament de Normandie, CNRS 3038 INC3M, SFR ICORE, 14032, Caen, France
| | - Patrick Dallemagne
- Normandie Université, UNICAEN, Centre d’Etudes et de Recherche sur le Médicament de Normandie, CNRS 3038 INC3M, SFR ICORE, 14032, Caen, France
| | - Arnaud Lehner
- Normandie Université, UNIROUEN, Laboratoire Glycobiologie et Matrice Extracellulaire Végétale EA4358, Fédération de Recherche “NORVEGE”- FED 4277, 76000 Rouen, France
| | - Jean-Claude Mollet
- Normandie Université, UNIROUEN, Laboratoire Glycobiologie et Matrice Extracellulaire Végétale EA4358, Fédération de Recherche “NORVEGE”- FED 4277, 76000 Rouen, France
| |
Collapse
|
7
|
Wu Y, Qin B, Feng K, Yan R, Kang E, Liu T, Shang Z. Extracellular ATP promoted pollen germination and tube growth of Nicotiana tabacum through promoting K + and Ca 2+ absorption. PLANT REPRODUCTION 2018; 31:399-410. [PMID: 29934740 DOI: 10.1007/s00497-018-0341-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 06/15/2018] [Indexed: 05/15/2023]
Abstract
Extracellular ATP (eATP) plays an essential role in plant growth, development, and stress tolerance. Here, we report that eATP participated in Nicotiana tabacum pollen germination (PG) and pollen tube growth (PTG) by regulating K+ and Ca2+ influx. Exogenous ATP or ADP effectively promoted PG and PTG in a dose-dependent manner; weakly hydrolysable ATP analog (ATPγS) showed a similar effect. AMP, adenosine, adenine, and phosphate did not affect PG or PTG. Within a certain range, higher concentrations of K+ or Ca2+ in the medium increased the effect of ATP in promoting PG and PTG. However, in mediums containing K+ or Ca2+ concentrations above this range, the effect of ATP was reversed, resulting in PG and PTG inhibition. Ca2+ chelators (EGTA), Ca2+ channel blockers, and K+ channel blockers suppressed ATP-promoted PG and PTG. Results from a patch clamp showed that ATP activated a K+ and Ca2+ influx in pollen protoplasts. These results suggest that, as an apoplastic signal, eATP may be involved in PG and PTG via regulating Ca2+ and K+ absorption.
Collapse
Affiliation(s)
- Yansheng Wu
- Hebei Key Laboratory of Molecular and Cellular Biology, Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, Hebei, China
- Department of Chemistry Engineering and Biological Technology, Xingtai University, Xingtai, 054001, Hebei, China
| | - Baozhi Qin
- Hebei Key Laboratory of Molecular and Cellular Biology, Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, Hebei, China
| | - Kaili Feng
- Hebei Key Laboratory of Molecular and Cellular Biology, Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, Hebei, China
| | - Ruolin Yan
- Hebei Key Laboratory of Molecular and Cellular Biology, Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, Hebei, China
| | - Erfang Kang
- Hebei Key Laboratory of Molecular and Cellular Biology, Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, Hebei, China
| | - Ting Liu
- Hebei Key Laboratory of Molecular and Cellular Biology, Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, Hebei, China
| | - Zhonglin Shang
- Hebei Key Laboratory of Molecular and Cellular Biology, Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, Hebei, China.
| |
Collapse
|
8
|
Herbell S, Gutermuth T, Konrad KR. An interconnection between tip-focused Ca 2+ and anion homeostasis controls pollen tube growth. PLANT SIGNALING & BEHAVIOR 2018; 13:e1529521. [PMID: 30307369 PMCID: PMC6279333 DOI: 10.1080/15592324.2018.1529521] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 09/17/2018] [Accepted: 09/18/2018] [Indexed: 05/12/2023]
Abstract
Plant reproduction is the basis for economically relevant food production. It relies on pollen tube (PTs) growth into the female flower organs for successful fertilization. The high cytosolic Ca2+ concentration ([Ca2+]cyt) at the PT tip is sensed by Ca2+-dependent protein kinases (CPKs) that in turn activate R- and S-type anion channels to control polar growth. Lanthanum, a blocker for plant Ca2+-permeable channels was used here to demonstrate a strict dependency for anion channel activation through high PT tip [Ca2+]cyt. We visualized this relationship by live-cell anion imaging and concurrent triggering of Ca2+-elevations with the two-electrode voltage-clamp (TEVC) technique. The anion efflux provoked by a TEVC-triggered [Ca2+]cyt increase was abolished by Lanthanum and was followed by an overall rise in the cytosolic anion concentration. An interrelation between Ca2+ and anion homeostasis occurred also on the transcript level of CPKs and anion channels. qRT-PCR analysis demonstrated a co-regulation of anion channels and CPKs in media with different Cl- and NO3- compositions. Our data provides strong evidence for the importance of a Ca2+-dependent anion channel regulation and point to a synchronized adjustment of CPK and anion channel transcript levels to fine-tune anion efflux at the PT tip.
Collapse
Affiliation(s)
- Sarah Herbell
- University of Wuerzburg, Julius-Von-Sachs Institute for Biosciences, Department of Botany I, Wuerzburg, Germany
| | - Timo Gutermuth
- University of Wuerzburg, Julius-Von-Sachs Institute for Biosciences, Department of Botany I, Wuerzburg, Germany
| | - Kai Robert Konrad
- University of Wuerzburg, Julius-Von-Sachs Institute for Biosciences, Department of Botany I, Wuerzburg, Germany
| |
Collapse
|
9
|
Barberini ML, Sigaut L, Huang W, Mangano S, Juarez SPD, Marzol E, Estevez J, Obertello M, Pietrasanta L, Tang W, Muschietti J. Calcium dynamics in tomato pollen tubes using the Yellow Cameleon 3.6 sensor. PLANT REPRODUCTION 2018; 31:159-169. [PMID: 29236154 DOI: 10.1007/s00497-017-0317-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 12/04/2017] [Indexed: 06/07/2023]
Abstract
In vitro tomato pollen tubes show a cytoplasmic calcium gradient that oscillates with the same period as growth. Pollen tube growth requires coordination between the tip-focused cytoplasmic calcium concentration ([Ca2+]cyt) gradient and the actin cytoskeleton. This [Ca2+]cyt gradient is necessary for exocytosis of small vesicles, which contributes to the delivery of new membrane and cell wall at the pollen tube tip. The mechanisms that generate and maintain this [Ca2+]cyt gradient are not completely understood. Here, we studied calcium dynamics in tomato (Solanum lycopersicum) pollen tubes using transgenic tomato plants expressing the Yellow Cameleon 3.6 gene under the pollen-specific promoter LAT52. We use tomato as an experimental model because tomato is a Solanaceous plant that is easy to transform, and has an excellent genomic database and genetic stock center, and unlike Arabidopsis, tomato pollen is a good system to do biochemistry. We found that tomato pollen tubes showed an oscillating tip-focused [Ca2+]cyt gradient with the same period as growth. Then, we used a pharmacological approach to disturb the intracellular Ca2+ homeostasis, evaluating how the [Ca2+]cyt gradient, pollen germination and in vitro pollen tube growth were affected. We found that cyclopiazonic acid (CPA), a drug that inhibits plant PIIA-type Ca2+-ATPases, increased [Ca2+]cyt in the subapical zone, leading to the disappearance of the Ca2+ oscillations and inhibition of pollen tube growth. In contrast, 2-aminoethoxydiphenyl borate (2-APB), an inhibitor of Ca2+ released from the endoplasmic reticulum to the cytoplasm in animals cells, completely reduced [Ca2+]cyt at the tip of the tube, blocked the gradient and arrested pollen tube growth. Although both drugs have antagonistic effects on [Ca2+]cyt, both inhibited pollen tube growth triggering the disappearance of the [Ca2+]cyt gradient. When CPA and 2-APB were combined, their individual inhibitory effects on pollen tube growth were partially compensated. Finally, we found that GsMTx-4, a peptide from spider venom that blocks stretch-activated Ca2+ channels, inhibited tomato pollen germination and had a heterogeneous effect on pollen tube growth, suggesting that these channels are also involved in the maintenance of the [Ca2+]cyt gradient. All these results indicate that tomato pollen tube is an excellent model to study calcium dynamics.
Collapse
Affiliation(s)
- María Laura Barberini
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, "Dr. Héctor Torres" (INGEBI-CONICET), Vuelta de Obligado 2490, C1428ADN, Buenos Aires, Argentina
| | - Lorena Sigaut
- Instituto de Física de Buenos Aires (IFIBA-CONICET), Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Güiraldes 2160, Ciudad Universitaria, Pabellón I, C1428EHA, Buenos Aires, Argentina
| | - Weijie Huang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom
| | - Silvina Mangano
- Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA-CONICET), Av. Patricias Argentinas 435, CP C1405BWE, Buenos Aires, Argentina
| | - Silvina Paola Denita Juarez
- Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA-CONICET), Av. Patricias Argentinas 435, CP C1405BWE, Buenos Aires, Argentina
| | - Eliana Marzol
- Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA-CONICET), Av. Patricias Argentinas 435, CP C1405BWE, Buenos Aires, Argentina
| | - José Estevez
- Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA-CONICET), Av. Patricias Argentinas 435, CP C1405BWE, Buenos Aires, Argentina
| | - Mariana Obertello
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, "Dr. Héctor Torres" (INGEBI-CONICET), Vuelta de Obligado 2490, C1428ADN, Buenos Aires, Argentina
| | - Lía Pietrasanta
- Instituto de Física de Buenos Aires (IFIBA-CONICET), Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Güiraldes 2160, Ciudad Universitaria, Pabellón I, C1428EHA, Buenos Aires, Argentina
- Centro de Microscopías Avanzadas, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Güiraldes 2160, Ciudad Universitaria, Pabellón I, C1428EHA, Buenos Aires, Argentina
| | - Weihua Tang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China
| | - Jorge Muschietti
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, "Dr. Héctor Torres" (INGEBI-CONICET), Vuelta de Obligado 2490, C1428ADN, Buenos Aires, Argentina.
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Güiraldes 2160, Ciudad Universitaria, Pabellón II, C1428EGA, Buenos Aires, Argentina.
| |
Collapse
|
10
|
Gutermuth T, Herbell S, Lassig R, Brosché M, Romeis T, Feijó JA, Hedrich R, Konrad KR. Tip-localized Ca 2+ -permeable channels control pollen tube growth via kinase-dependent R- and S-type anion channel regulation. THE NEW PHYTOLOGIST 2018; 218:1089-1105. [PMID: 29522235 DOI: 10.1111/nph.15067] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 01/18/2018] [Indexed: 05/26/2023]
Abstract
Pollen tubes (PTs) are characterized by having tip-focused cytosolic calcium ion (Ca2+ ) concentration ([Ca2+ ]cyt ) gradients, which are believed to control PT growth. However, the mechanisms by which the apical [Ca2+ ]cyt orchestrates PT growth are not well understood. Here, we aimed to identify these mechanisms by combining reverse genetics, cell biology, electrophysiology, and live-cell Ca2+ and anion imaging. We triggered Ca2+ -channel activation by applying hyperpolarizing voltage pulses and observed that the evoked [Ca2+ ]cyt increases were paralleled by high anion channel activity and a decrease in the cytosolic anion concentration at the PT tip. We confirmed a functional correlation between these patterns by showing that inhibition of Ca2+ -permeable channels eliminated the [Ca2+ ]cyt increase, resulting in the abrogation of anion channel activity via Ca2+ -dependent protein kinases (CPKs). Functional characterization of CPK and anion-channel mutants revealed a CPK2/20/6-dependent activation of SLAH3 and ALMT12/13/14 anion channels. The impaired growth phenotypes of anion channel and CPK mutants support the physiological significance of a kinase- and Ca2+ -dependent pathway to control PT growth via anion channel activation. Other than unveiling this functional link, our membrane hyperpolarization method allows for unprecedented manipulation of the [Ca2+ ]cyt gradient or oscillations in the PT tips and opens an array of opportunities for channel screenings.
Collapse
Affiliation(s)
- Timo Gutermuth
- Department of Botany I, Julius-Von-Sachs Institute for Biosciences, University of Wuerzburg, 97082, Wuerzburg, Germany
| | - Sarah Herbell
- Department of Botany I, Julius-Von-Sachs Institute for Biosciences, University of Wuerzburg, 97082, Wuerzburg, Germany
| | - Roman Lassig
- Plant Biochemistry, Dahlem Centre of Plant Sciences, FU Berlin, Königin-Luise-Straße 12/16, 14195, Berlin, Germany
| | - Mikael Brosché
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014, Helsinki, Finland
- Institute of Technology, University of Tartu, Nooruse 1, 50411, Tartu, Estonia
| | - Tina Romeis
- Plant Biochemistry, Dahlem Centre of Plant Sciences, FU Berlin, Königin-Luise-Straße 12/16, 14195, Berlin, Germany
| | - José Alberto Feijó
- Department of Cell Biology & Molecular Genetics, University of Maryland, 2136 Bioscience Research Building, College Park, MD, 20742-5815, USA
| | - Rainer Hedrich
- Department of Botany I, Julius-Von-Sachs Institute for Biosciences, University of Wuerzburg, 97082, Wuerzburg, Germany
| | - Kai Robert Konrad
- Department of Botany I, Julius-Von-Sachs Institute for Biosciences, University of Wuerzburg, 97082, Wuerzburg, Germany
| |
Collapse
|
11
|
Konrad KR, Maierhofer T, Hedrich R. Spatio-temporal Aspects of Ca2+ Signalling: Lessons from Guard Cells and Pollen Tubes. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:4986225. [PMID: 29701811 DOI: 10.1093/jxb/ery154] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Indexed: 05/06/2023]
Abstract
Changes in cytosolic Ca2+ concentration ([Ca2+]cyt) serve to transmit information in eukaryotic cells. The involvement of this second messenger in plant cell growth as well as osmotic- and water relations is well established. After almost 40 years of intense research on the coding and decoding of plant Ca2+ signals, numerous proteins involved in Ca2+ action have been identified. However, we are still far from understanding the complexity of Ca2+ networks. New in vivo Ca2+ imaging techniques combined with molecular genetics allow visualisation of spatio-temporal aspects of Ca2+ signalling. In parallel, cell biology together with protein biochemistry and electrophysiology are able to dissect information processing by this second messenger in space and time. Here we focus on the time-resolved changes in cellular events upon Ca2+ signals, concentrating on the two best-studied cell types, pollen tubes and guard cells. We put their signalling networks side by side, compare them with those of other cell types and discuss rapid signalling in the context of Ca2+ transients and oscillations to regulate ion homeostasis.
Collapse
Affiliation(s)
- K R Konrad
- University of Wuerzburg, Julius-Von-Sachs Institute for Biosciences, Department of Botany I, Wuerzburg, Germany
| | - T Maierhofer
- University of Wuerzburg, Julius-Von-Sachs Institute for Biosciences, Department of Botany I, Wuerzburg, Germany
| | - R Hedrich
- University of Wuerzburg, Julius-Von-Sachs Institute for Biosciences, Department of Botany I, Wuerzburg, Germany
| |
Collapse
|
12
|
Martos GG, Mamaní A, Filippone MP, Castagnaro AP, Díaz Ricci JC. The ellagitannin HeT induces electrolyte leakage, calcium influx and the accumulation of nitric oxide and hydrogen peroxide in strawberry. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2018; 123:400-405. [PMID: 29306187 DOI: 10.1016/j.plaphy.2017.12.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 11/30/2017] [Accepted: 12/22/2017] [Indexed: 06/07/2023]
Abstract
HeT (1-0-galloyl-2,3; 4,6-bis-hexahydroxydiphenoyl-β-D-glucopyranose) is a penta-esterified ellagitannin obtained from strawberry leaves. Previous studies have shown that foliar application of HeT prior to inoculation with a virulent pathogen increases the resistance toward Colletotrichum acutatum in strawberry plants and to Xanthomonas citri subsp. citri in lemon plants. In this work we report that HeT induces an immediate leak of electrolytes, the hyperpolarization of the cellular membrane, a rapid Ca2+ influx to the cytoplasm during the first few seconds, which in turn modulates the accumulation of nitric oxide 5 min after treatment. At longer times, a biphasic accumulation of H2O2 with peaks at 2 and 5 h post treatment could be observed. In addition, HeT elicited the increase of alternative oxidase capacity during the first 12 h post treatment.
Collapse
Affiliation(s)
- Gustavo Gabriel Martos
- Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, UNT, Chacabuco 461, T4000ILI, San Miguel de Tucumán, Argentina
| | - Alicia Mamaní
- Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, UNT, Chacabuco 461, T4000ILI, San Miguel de Tucumán, Argentina
| | - María Paula Filippone
- Sección Biotecnología de la Estación Experimental Agroindustrial Obispo Colombres (EEAOC)-Unidad Asociada al INSIBIO, Av. William Cross 3150, Las Talitas, 4101, Tucumán, Argentina
| | - Atilio Pedro Castagnaro
- Sección Biotecnología de la Estación Experimental Agroindustrial Obispo Colombres (EEAOC)-Unidad Asociada al INSIBIO, Av. William Cross 3150, Las Talitas, 4101, Tucumán, Argentina
| | - Juan Carlos Díaz Ricci
- Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, UNT, Chacabuco 461, T4000ILI, San Miguel de Tucumán, Argentina.
| |
Collapse
|
13
|
Demidchik V, Shabala S. Mechanisms of cytosolic calcium elevation in plants: the role of ion channels, calcium extrusion systems and NADPH oxidase-mediated 'ROS-Ca 2+ Hub'. FUNCTIONAL PLANT BIOLOGY : FPB 2018; 45:9-27. [PMID: 32291018 DOI: 10.1071/fp16420] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 12/07/2016] [Indexed: 05/22/2023]
Abstract
Elevation in the cytosolic free calcium is crucial for plant growth, development and adaptation. Calcium influx into plant cells is mediated by Ca2+ depolarisation-activated, hyperpolarisation-activated and voltage-independent Ca2+-permeable channels (DACCs, HACCs and VICCs respectively). These channels are encoded by the following gene families: (1) cyclic nucleotide-gated channels (CNGCs), (2) ionotropic glutamate receptors (GLRs), (3) annexins, (4) 'mechanosensitive channels of small (MscS) conductance'-like channels (MSLs), (5) 'mid1-complementing activity' channels (MCAs), Piezo channels, and hyperosmolality-induced [Ca2+]cyt. channel 1 (OSCA1). Also, a 'tandem-pore channel1' (TPC1) catalyses Ca2+ efflux from the vacuole in response to the plasma membrane-mediated Ca2+ elevation. Recent experimental data demonstrated that Arabidopsis thaliana (L.) Heynh. CNGCs 2, 5-10, 14, 16 and 18, GLRs 1.2, 3.3, 3.4, 3.6 and 3.7, TPC1, ANNEXIN1, MSL9 and MSL10,MCA1 and MCA2, OSCA1, and some their homologues counterparts in other species, are responsible for Ca2+ currents and/or cytosolic Ca2+ elevation. Extrusion of Ca2+ from the cytosol is mediated by Ca2+-ATPases and Ca2+/H+ exchangers which were recently examined at the level of high resolution crystal structure. Calcium-activated NADPH oxidases and reactive oxygen species (ROS)-activated Ca2+ conductances form a self-amplifying 'ROS-Ca2+hub', enhancing and transducing Ca2+ and redox signals. The ROS-Ca2+ hub contributes to physiological reactions controlled by ROS and Ca2+, demonstrating synergism and unity of Ca2+ and ROS signalling mechanisms.
Collapse
Affiliation(s)
- Vadim Demidchik
- Department of Plant Cell Biology and Bioengineering, Biological Faculty, Belarusian State University, 4 Independence Avenue, Minsk, 220030, Belarus
| | - Sergey Shabala
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart, Tas. 7001, Australia
| |
Collapse
|
14
|
Qu H, Guan Y, Wang Y, Zhang S. PLC-Mediated Signaling Pathway in Pollen Tubes Regulates the Gametophytic Self-incompatibility of Pyrus Species. FRONTIERS IN PLANT SCIENCE 2017; 8:1164. [PMID: 28729872 PMCID: PMC5498517 DOI: 10.3389/fpls.2017.01164] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Accepted: 06/16/2017] [Indexed: 05/27/2023]
Abstract
Among the Rosaceae species, the gametophytic self-incompatibility (GSI) is controlled by a single multi-allelic S locus, which is composed of the pistil-S and pollen-S genes. The pistil-S gene encodes a polymorphic ribonuclease (S-RNase), which is essential for identifying self-pollen. However, the S-RNase system has not been fully characterized. In this study, the self-S-RNase inhibited the Ca2+-permeable channel activity at pollen tube apices and the selectively decreased phospholipase C (PLC) activity in the plasma membrane of Pyrus pyrifolia pollen tubes. Self-S-RNase decreased the Ca2+ influx through a PLC-mediated signaling pathway. Phosphatidylinositol-specific PLC has a 26-amino acid insertion in pollen tubes of the 'Jinzhuili' cultivar, which is a spontaneous self-compatible mutant of the 'Yali' cultivar. 'Yali' plants exhibit a typical S-RNase-based GSI. Upon self-pollination, PLC gene expression is significantly higher in 'Jinzhuili' pollen tubes than that in 'Yali' pollen tubes. Moreover, the PLC in pollen tubes can only interact with one of the two types of S-RNase from the style. In the Pyrus x bretschneideri Rehd, the PLC directly interacted with the S7-RNase in the pollen tube, but not with the S34-RNase. Collectively, our results reveal that the effects of S-RNase on PLC activity are required for S-specific pollen rejection, and that PLC-IP3 participates in the self-incompatibility reaction of Pyrus species.
Collapse
Affiliation(s)
- Haiyong Qu
- College of Horticulture, Qingdao Agricultural UniversityQingdao, China
| | - Yaqin Guan
- College of Horticulture, Qingdao Agricultural UniversityQingdao, China
| | - Yongzhang Wang
- College of Horticulture, Qingdao Agricultural UniversityQingdao, China
| | - Shaolin Zhang
- College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| |
Collapse
|
15
|
Schoenaers S, Balcerowicz D, Costa A, Vissenberg K. The Kinase ERULUS Controls Pollen Tube Targeting and Growth in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2017; 8:1942. [PMID: 29184563 PMCID: PMC5694544 DOI: 10.3389/fpls.2017.01942] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 10/27/2017] [Indexed: 05/09/2023]
Abstract
In this paper, we describe the role of the receptor-like kinase ERULUS (ERU) in PT growth of Arabidopsis thaliana. In silico analysis and transcriptional reporter lines revealed that ERU is only expressed in pollen and root hairs (RHs), making it a tip growth-specific kinase. Deviations from Mendelian inheritance were observed in the offspring of self-pollinated heterozygous eru plants. We found that in vivo eru PT targeting was disturbed, providing a possible explanation for the observed decrease in eru fertilization competitiveness. Extracellular calcium perception and intracellular calcium dynamics lie at the basis of in vivo pollen tube (PT) tip growth and guidance. In vitro, ERU loss-of-function lines displayed no obvious PT phenotype, unless grown on low extracellular calcium ([Ca2+]ext) medium. When grown at 12 the normal [Ca2+]ext, eru PTs grew 37% slower relative to WT PTs. Visualization of cytoplasmic [Ca2+]cyt oscillations using the Yellow Cameleon 3.6 (YC3.6) calcium sensor showed that, unlike in WT PTs, eru apical [Ca2+]cyt oscillations occur at a lower frequency when grown at lower [Ca2+]ext, consistent with the observed reduced growth velocity. Our results show that the tip growth-specific kinase ERULUS is involved in regulating Ca2+-dependent PT growth, and most importantly, fertilization efficiency through successful PT targeting to the ovules.
Collapse
Affiliation(s)
- Sébastjen Schoenaers
- Integrated Molecular Plant Physiology Research, University of Antwerp, Antwerp, Belgium
| | - Daria Balcerowicz
- Integrated Molecular Plant Physiology Research, University of Antwerp, Antwerp, Belgium
| | - Alex Costa
- Department of Biosciences, University of Milan, Milan, Italy
- Institute of Biophysics, Consiglio Nazionale delle Ricerche, Milan, Italy
| | - Kris Vissenberg
- Integrated Molecular Plant Physiology Research, University of Antwerp, Antwerp, Belgium
- Plant Biochemistry and Biotechnology Lab, Technological Educational Institute of Crete: University of Applied Sciences, Crete, Greece
- *Correspondence: Kris Vissenberg,
| |
Collapse
|
16
|
The role of Ca 2+ and Ca 2+ channels in the gametophytic self-incompatibility of Pyrus pyrifolia. Cell Calcium 2016; 60:299-308. [DOI: 10.1016/j.ceca.2016.06.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 06/23/2016] [Indexed: 11/15/2022]
|
17
|
Breygina MA, Abramochkin DV, Maksimov NM, Yermakov IP. Hydrogen peroxide affects ion channels in lily pollen grain protoplasts. PLANT BIOLOGY (STUTTGART, GERMANY) 2016; 18:761-7. [PMID: 27115728 DOI: 10.1111/plb.12470] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 04/22/2016] [Indexed: 05/22/2023]
Abstract
Ion homeostasis plays a central role in polarisation and polar growth. In several cell types ion channels are controlled by reactive oxygen species (ROS). One of the most important cells in the plant life cycle is the male gametophyte, which grows under the tight control of both ion fluxes and ROS balance. The precise relationship between these two factors in pollen tubes has not been completely elucidated, and in pollen grains it has never been studied to date. In the present study we used a simple model - protoplasts obtained from lily pollen grains at the early germination stage - to reveal the effect of H2 O2 on cation fluxes crucial for pollen germination. Here we present direct evidence for two ROS-sensitive currents on the pollen grain plasma membrane: the hyperpolarisation-activated calcium current, which is strongly enhanced by H2 O2 , and the outward potassium current, which is modestly enhanced by H2 O2 . We used low concentrations of H2 O2 that do not cause an intracellular oxidative burst and do not damage cells, as demonstrated with fluorescent staining.
Collapse
Affiliation(s)
- M A Breygina
- Lomonosov Moscow State University, Moscow, Russia
- Pirogov Russian National Research Medical University, Moscow, Russia
| | - D V Abramochkin
- Lomonosov Moscow State University, Moscow, Russia
- Pirogov Russian National Research Medical University, Moscow, Russia
| | - N M Maksimov
- Lomonosov Moscow State University, Moscow, Russia
| | - I P Yermakov
- Lomonosov Moscow State University, Moscow, Russia
| |
Collapse
|
18
|
Zahid KR, Ali F, Shah F, Younas M, Shah T, Shahwar D, Hassan W, Ahmad Z, Qi C, Lu Y, Iqbal A, Wu W. Response and Tolerance Mechanism of Cotton Gossypium hirsutum L. to Elevated Temperature Stress: A Review. FRONTIERS IN PLANT SCIENCE 2016; 7:937. [PMID: 27446165 PMCID: PMC4927942 DOI: 10.3389/fpls.2016.00937] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 06/13/2016] [Indexed: 05/23/2023]
Abstract
Cotton is an important multipurpose crop which is highly sensitive to both biotic and abiotic stresses. Proper management of this cash crop requires systematic understanding of various environmental conditions that are vital to yield and quality. High temperature stress can severely affect the viability of pollens and anther indehiscence, which leads to significant yield losses. Cotton can respond to withstand adverse environmental condition in several phases among which the accumulation of chemicals is extremely vital. Calcium, kinases, reactive oxygen species, carbohydrate, transcription factors, gene expression regulation, and plant hormones signaling pathways are playing a handy role in activating the major genes responsible to encounter and defend elevated temperature stress. The production of heat shock proteins is up-regulated when crops are unleashed to high temperature stress. Molecular breeding can play a functional role to identify superior genes for all the important attributes as well as provide breeder ready markers for developing ideotypes. The development of high-temperature resistant transgenic cultivars of cotton can grant a stability benefit and can also ameliorate the production capacity in response to elevated temperature.
Collapse
Affiliation(s)
- Kashif Rafiq Zahid
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal UniversityWuhan, China
| | - Farhan Ali
- Cereal Crops Research InstitutePirsabak, Nowshera, Pakistan
| | - Farooq Shah
- Department of Agriculture, Abdul Wali Khan University MardanKhyber Pakhtunkhwa, Pakistan
| | - Muhammad Younas
- Department of Biotechnology, Mohi-ud-Din Islamic UniversityAzad Jammu and Kashmir, Pakistan
| | - Tariq Shah
- Department of Agricultural Economics and Management, Huazhong Agricultural UniversityWuhan, China
| | - Durri Shahwar
- Department of Plant Breeding and Genetics, University of SwabiKhyber Pakhtunkhwa, Pakistan
| | - Waseem Hassan
- Department of Soil and Environmental Sciences, Muhammad Nawaz Shareef University of AgricultureMultan, Pakistan
| | - Zahoor Ahmad
- Key Lab of Crop Disease Monitoring and Safety Control, Huazhong Agricultural UniversityWuhan, China
| | - Chao Qi
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal UniversityWuhan, China
| | - Yanli Lu
- Maize Research Institute, Sichuan Agricultural UniversityWenjian Sichuan, China
| | - Amjad Iqbal
- Department of Agriculture, Abdul Wali Khan University MardanKhyber Pakhtunkhwa, Pakistan
| | - Wei Wu
- College of Agronomy, Northwest A&F UniversityYangling, China
| |
Collapse
|
19
|
Qu H, Xing W, Wu F, Wang Y. Rapid and Inexpensive Method of Loading Fluorescent Dye into Pollen Tubes and Root Hairs. PLoS One 2016; 11:e0152320. [PMID: 27055240 PMCID: PMC4824429 DOI: 10.1371/journal.pone.0152320] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 03/11/2016] [Indexed: 01/07/2023] Open
Abstract
The most direct technique for studying calcium, which is an essential element for pollen tube growth, is Ca2+ imaging. Because membranes are relatively impermeable, the loading of fluorescent Ca2+ probes into plant cells is a challenging task. Thus, we have developed a new method of loading fluo-4 acetoxymethyl ester into cells that uses a cell lysis solution to improve the introduction of this fluorescent dye into pollen tubes. Using this method, the loading times were reduced to 15 min. Furthermore, loading did not have to be performed at low (4°C) temperatures and was successful at room temperature, and pluronic F-127 was not required, which would theoretically allow for the loading of an unlimited number of cells. Moreover, the method can also be used to fluorescently stain root hairs.
Collapse
Affiliation(s)
- Haiyong Qu
- College of Horticulture, Qingdao Agricultural University, No. 700 Changcheng Road, Chengyang, Qingdao City, Shandong Province, China
- * E-mail:
| | - Wenxi Xing
- Department of Horticulture, Qingdao Agricultural University, China, Qingdao City, China
| | - Fenfen Wu
- Department of Horticulture, Qingdao Agricultural University, China, Qingdao City, China
| | - Yongzhang Wang
- Department of Horticulture, Qingdao Agricultural University, China, Qingdao City, China
| |
Collapse
|
20
|
Rounds CM, Hepler PK, Winship LJ. The apical actin fringe contributes to localized cell wall deposition and polarized growth in the lily pollen tube. PLANT PHYSIOLOGY 2014; 166:139-51. [PMID: 25037212 PMCID: PMC4149702 DOI: 10.1104/pp.114.242974] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 07/08/2014] [Indexed: 05/19/2023]
Abstract
In lily (Lilium formosanum) pollen tubes, pectin, a major component of the cell wall, is delivered through regulated exocytosis. The targeted transport and secretion of the pectin-containing vesicles may be controlled by the cortical actin fringe at the pollen tube apex. Here, we address the role of the actin fringe using three different inhibitors of growth: brefeldin A, latrunculin B, and potassium cyanide. Brefeldin A blocks membrane trafficking and inhibits exocytosis in pollen tubes; it also leads to the degradation of the actin fringe and the formation of an aggregate of filamentous actin at the base of the clear zone. Latrunculin B, which depolymerizes filamentous actin, markedly slows growth but allows focused pectin deposition to continue. Of note, the locus of deposition shifts frequently and correlates with changes in the direction of growth. Finally, potassium cyanide, an electron transport chain inhibitor, briefly stops growth while causing the actin fringe to completely disappear. Pectin deposition continues but lacks focus, instead being delivered in a wide arc across the pollen tube tip. These data support a model in which the actin fringe contributes to the focused secretion of pectin to the apical cell wall and, thus, to the polarized growth of the pollen tube.
Collapse
Affiliation(s)
- Caleb M Rounds
- Department of Biology, University of Massachusetts, Amherst, Massachusetts 01003 (C.M.R., P.K.H.); andSchool of Natural Science, Hampshire College, Amherst, Massachusetts 01002 (L.J.W.)
| | - Peter K Hepler
- Department of Biology, University of Massachusetts, Amherst, Massachusetts 01003 (C.M.R., P.K.H.); andSchool of Natural Science, Hampshire College, Amherst, Massachusetts 01002 (L.J.W.)
| | - Lawrence J Winship
- Department of Biology, University of Massachusetts, Amherst, Massachusetts 01003 (C.M.R., P.K.H.); andSchool of Natural Science, Hampshire College, Amherst, Massachusetts 01002 (L.J.W.)
| |
Collapse
|
21
|
Wu J, Qin X, Tao S, Jiang X, Liang YK, Zhang S. Long-chain base phosphates modulate pollen tube growth via channel-mediated influx of calcium. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 79:507-516. [PMID: 24905418 DOI: 10.1111/tpj.12576] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 05/22/2014] [Accepted: 05/28/2014] [Indexed: 06/03/2023]
Abstract
Long-chain base phosphates (LCBPs) have been correlated with amounts of crucial biological processes ranging from cell proliferation to apoptosis in animals. However, their functions in plants remain largely unknown. Here, we report that LCBPs, sphingosine-1-phosphate (S1P) and phytosphingosine-1-phosphate (Phyto-S1P), modulate pollen tube growth in a concentration-dependent bi-phasic manner. The pollen tube growth in the stylar transmitting tissue was promoted by SPHK1 overexpression (SPHK1-OE) but dampened by SPHK1 knockdown (SPHK1-KD) compared with wild-type of Arabidopsis; however, there was no detectable effect on in vitro pollen tube growth caused by misexpression of SPHK1. Interestingly, exogenous S1P or Phyto-S1P applications could increase the pollen tube growth rate in SPHK1-OE, SPHK1-KD and wild-type of Arabidopsis. Calcium ion (Ca(2+) )-imaging analysis showed that S1P triggered a remarkable increase in cytosolic Ca(2+) concentration in pollen. Extracellular S1P induced hyperpolarization-activated Ca(2+) currents in the pollen plasma membrane, and the Ca(2+) current activation was mediated by heterotrimeric G proteins. Moreover, the S1P-induced increase of cytosolic free Ca(2+) inhibited the influx of potassium ions in pollen tubes. Our findings suggest that LCBPs functions in a signaling cascade that facilitates Ca(2+) influx and modulates pollen tube growth.
Collapse
Affiliation(s)
- Juyou Wu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | | | | | | | | | | |
Collapse
|
22
|
Jiang X, Gao Y, Zhou H, Chen J, Wu J, Zhang S. Apoplastic calmodulin promotes self-incompatibility pollen tube growth by enhancing calcium influx and reactive oxygen species concentration in Pyrus pyrifolia. PLANT CELL REPORTS 2014; 33:255-63. [PMID: 24145911 DOI: 10.1007/s00299-013-1526-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Revised: 10/03/2013] [Accepted: 10/09/2013] [Indexed: 05/17/2023]
Abstract
Calmodulin (CaM) has been associated with various physiological and developmental processes in plants, including pollen tube growth. In this study, we showed that CaM regulated the pear pollen tube growth in a concentration-dependent bi-phasic response. Using a whole-cell patch-clamp configuration, we showed that apoplastic CaM induced a hyperpolarization-activated calcium ion (Ca²⁺) current, and anti-CaM largely inhibited this type of Ca²⁺ current. Moreover, upon anti-CaM treatment, the reactive oxygen species (ROS) concentration decreased and actin filaments depolymerized in the pollen tube. Interestingly, CaM could partially rescue the inhibition of self-incompatible pear pollen tube growth. This phenotype could be mediated by CaM-enhanced pollen plasma membrane Ca²⁺ current, tip-localized ROS concentration and stabilized actin filaments. These data indicated that Ca²⁺, ROS and actin filaments were involved with CaM in regulating pollen tube growth and provide a potential way for overcoming pear self-incompatibility.
Collapse
Affiliation(s)
- Xueting Jiang
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, No 6. Tongwei Road, Nanjing, 210095, China
| | | | | | | | | | | |
Collapse
|
23
|
Chen DH, Acharya BR, Liu W, Zhang W. Interaction between Calcium and Actin in Guard Cell and Pollen Signaling Networks. PLANTS (BASEL, SWITZERLAND) 2013; 2:615-34. [PMID: 27137395 PMCID: PMC4844389 DOI: 10.3390/plants2040615] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 09/25/2013] [Accepted: 09/26/2013] [Indexed: 12/17/2022]
Abstract
Calcium (Ca(2+)) plays important roles in plant growth, development, and signal transduction. It is a vital nutrient for plant physical design, such as cell wall and membrane, and also serves as a counter-cation for biochemical, inorganic, and organic anions, and more particularly, its concentration change in cytosol is a ubiquitous second messenger in plant physiological signaling in responses to developmental and environmental stimuli. Actin cytoskeleton is well known for its importance in cellular architecture maintenance and its significance in cytoplasmic streaming and cell division. In plant cell system, the actin dynamics is a process of polymerization and de-polymerization of globular actin and filamentous actin and that acts as an active regulator for calcium signaling by controlling calcium evoked physiological responses. The elucidation of the interaction between calcium and actin dynamics will be helpful for further investigation of plant cell signaling networks at molecular level. This review mainly focuses on the recent advances in understanding the interaction between the two aforementioned signaling components in two well-established model systems of plant, guard cell, and pollen.
Collapse
Affiliation(s)
- Dong-Hua Chen
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, College of Life Sciences, Shandong University, Jinan 250100, Shandong, China.
| | - Biswa R Acharya
- Biology Department, Penn State University, University Park, PA 16802, USA.
| | - Wei Liu
- High-Tech Research Center, Shandong Academy of Agricultural Sciences, Key Laboratory of Genetic Improvement, Ecology and Physiology of Crops, Jinan 250100, Shandong, China.
| | - Wei Zhang
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, College of Life Sciences, Shandong University, Jinan 250100, Shandong, China.
| |
Collapse
|
24
|
Inheritance of hetero-diploid pollen S-haplotype in self-compatible tetraploid Chinese cherry (Prunus pseudocerasus Lindl). PLoS One 2013; 8:e61219. [PMID: 23596519 PMCID: PMC3626605 DOI: 10.1371/journal.pone.0061219] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 03/08/2013] [Indexed: 11/19/2022] Open
Abstract
The breakdown of self-incompatibility, which could result from the accumulation of non-functional S-haplotypes or competitive interaction between two different functional S-haplotypes, has been studied extensively at the molecular level in tetraploid Rosaceae species. In this study, two tetraploid Chinese cherry (Prunus pseudocerasus) cultivars and one diploid sweet cherry (Prunus avium) cultivar were used to investigate the ploidy of pollen grains and inheritance of pollen-S alleles. Genetic analysis of the S-genotypes of two intercross-pollinated progenies showed that the pollen grains derived from Chinese cherry cultivars were hetero-diploid, and that the two S-haplotypes were made up of every combination of two of the four possible S-haplotypes. Moreover, the distributions of single S-haplotypes expressed in self- and intercross-pollinated progenies were in disequilibrium. The number of individuals of the two different S-haplotypes was unequal in two self-pollinated and two intercross-pollinated progenies. Notably, the number of individuals containing two different S-haplotypes (S1- and S5-, S5- and S8-, S1- and S4-haplotype) was larger than that of other individuals in the two self-pollinated progenies, indicating that some of these hetero-diploid pollen grains may have the capability to inactivate stylar S-RNase inside the pollen tube and grow better into the ovaries.
Collapse
|
25
|
Zhao LN, Shen LK, Zhang WZ, Zhang W, Wang Y, Wu WH. Ca2+-dependent protein kinase11 and 24 modulate the activity of the inward rectifying K+ channels in Arabidopsis pollen tubes. THE PLANT CELL 2013; 25:649-61. [PMID: 23449501 PMCID: PMC3608784 DOI: 10.1105/tpc.112.103184] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 01/03/2013] [Accepted: 02/07/2013] [Indexed: 05/18/2023]
Abstract
Potassium (K(+)) influx into pollen tubes via K(+) transporters is essential for pollen tube growth; however, the mechanism by which K(+) transporters are regulated in pollen tubes remains unknown. Here, we report that Arabidopsis thaliana Ca(2+)-dependent protein kinase11 (CPK11) and CPK24 are involved in Ca(2+)-dependent regulation of the inward K(+) (K(+)in) channels in pollen tubes. Using patch-clamp analysis, we demonstrated that K(+)in currents of pollen tube protoplasts were inhibited by elevated [Ca(2+)]cyt. However, disruption of CPK11 or CPK24 completely impaired the Ca(2+)-dependent inhibition of K(+)in currents and enhanced pollen tube growth. Moreover, the cpk11 cpk24 double mutant exhibited similar phenotypes as the corresponding single mutants, suggesting that these two CDPKs function in the same signaling pathway. Bimolecular fluorescence complementation and coimmunoprecipitation experiments showed that CPK11 could interact with CPK24 in vivo. Furthermore, CPK11 phosphorylated the N terminus of CPK24 in vitro, suggesting that these two CDPKs work together as part of a kinase cascade. Electrophysiological assays demonstrated that the Shaker pollen K(+)in channel is the main contributor to pollen tube K(+)in currents and acts as the downstream target of the CPK11-CPK24 pathway. We conclude that CPK11 and CPK24 together mediate the Ca(2+)-dependent inhibition of K(+)in channels and participate in the regulation of pollen tube growth in Arabidopsis.
Collapse
Affiliation(s)
| | | | | | | | - Yi Wang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, National Plant Gene Research Centre, China Agricultural University, Beijing 100193, China
| | - Wei-Hua Wu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, National Plant Gene Research Centre, China Agricultural University, Beijing 100193, China
| |
Collapse
|
26
|
Steinhorst L, Kudla J. Calcium - a central regulator of pollen germination and tube growth. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:1573-81. [PMID: 23072967 DOI: 10.1016/j.bbamcr.2012.10.009] [Citation(s) in RCA: 193] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 10/01/2012] [Accepted: 10/06/2012] [Indexed: 12/30/2022]
Abstract
Pollen tubes grow rapidly by very fast rates and reach extended lengths to bring about fertilization during plant reproduction. The pollen tube grows exclusively at its tip. Fundamental for such local, tip-focused growth are the presence of internal gradients and transmembrane fluxes of ions. Consequently, vegetative pollen tube cells are an excellent single cell model system to investigate cell biological processes of vesicle transport, cytoskeleton reorganization and regulation of ion transport. The second messenger Ca(2+) has emerged as a central and crucial modulator that not only regulates but also integrates the coordination each of these processes. In this review we reflect on recent advances in our understanding of the mechanisms of Ca(2+) function in pollen tube growth, focusing on its role in basic cellular processes such as control of cell growth, vesicular transport and intracellular signaling by localized gradients of second messengers. In particular we discuss new insights into the identity and role of Ca(2+) conductive ion channels and present experimental addressable hypotheses about their regulation. This article is part of a Special Issue entitled:12th European Symposium on Calcium.
Collapse
Affiliation(s)
- Leonie Steinhorst
- Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, Münster, Germany
| | | |
Collapse
|
27
|
Gao F, Han X, Wu J, Zheng S, Shang Z, Sun D, Zhou R, Li B. A heat-activated calcium-permeable channel--Arabidopsis cyclic nucleotide-gated ion channel 6--is involved in heat shock responses. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 70:1056-69. [PMID: 22372427 DOI: 10.1111/j.1365-313x.2012.04969.x] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
An increased concentration of cytosolic calcium ions (Ca²⁺) is an early response by plant cells to heat shock. However, the molecular mechanism underlying the heat-induced initial Ca²⁺ response in plants is unclear. In this study, we identified and characterized a heat-activated Ca²⁺-permeable channel in the plasma membrane of Arabidopsis thaliana root protoplasts using reverse genetic analysis and the whole-cell patch-clamp technique. The results indicated that A. thaliana cyclic nucleotide-gated ion channel 6 (CNGC6) mediates heat-induced Ca²⁺ influx and facilitates expression of heat shock protein (HSP) genes and the acquisition of thermotolerance. GUS and GFP reporter assays showed that CNGC6 expression is ubiquitous in A. thaliana, and the protein is localized to the plasma membrane of cells. Furthermore, it was found that the level of cytosolic cAMP was increased by a mild heat shock, that CNGC6 was activated by cytosolic cAMP, and that exogenous cAMP promoted the expression of HSP genes. The results reveal the role of cAMP in transduction of heat shock signals in plants. The correlation of an increased level of cytosolic cAMP in a heat-shocked plant with activation of the Ca²⁺ channels and downstream expression of HSP genes sheds some light on how plants transduce a heat stimulus into a signal cascade that leads to a heat shock response.
Collapse
Affiliation(s)
- Fei Gao
- Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang 050024, China
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Hepler PK, Kunkel JG, Rounds CM, Winship LJ. Calcium entry into pollen tubes. TRENDS IN PLANT SCIENCE 2012; 17:32-8. [PMID: 22104406 DOI: 10.1016/j.tplants.2011.10.007] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Revised: 10/20/2011] [Accepted: 10/25/2011] [Indexed: 05/22/2023]
Abstract
Growing pollen tubes require calcium to maintain a tip-focused cytosolic gradient and as a constituent of the constantly expanding cell wall. Advances in cell and molecular biology as well as electrophysiology implicate several candidate channels and receptors in the flow of calcium into the cell. In this review we discuss the channels that have been identified and consider the role of the growing tip cell wall acting as a sink for calcium thus accounting for differences in oscillatory phase between influx measured on the outside of the cell and changes in tip concentration inside the cell. We also briefly draw attention to uptake mechanisms that restrict and shape the calcium signature in the growing pollen tube.
Collapse
Affiliation(s)
- Peter K Hepler
- Biology Department, University of Massachusetts, Amherst, MA 01003, USA.
| | | | | | | |
Collapse
|
29
|
Qu H, Jiang X, Shi Z, Liu L, Zhang S. Fast loading ester fluorescent Ca2+ and pH indicators into pollen of Pyrus pyrifolia. JOURNAL OF PLANT RESEARCH 2012; 125:185-95. [PMID: 21789557 DOI: 10.1007/s10265-011-0440-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2011] [Accepted: 05/23/2011] [Indexed: 05/23/2023]
Abstract
Loading of Ca(2+)-sensitive fluorescent probes into plant cells is an essential step to measure activities of free Ca(2+) ions in cytoplasm with a fluorescent imaging technique. Fluo-3 is one of the most suitable Ca(2+) indicators for CLSM. We loaded pollen with fluo-3/AM at three different temperatures. Fluo-3/AM was successfully loaded into pollen at both low (4°C) and high (37°C) temperatures. However, high loading temperature was best suited for pollen, because germination rate of pollen and growth of pollen tubes were relatively little impaired and loading time was shortened. Moreover, Ca(2+) distribution increased in the three apertures of pollen after hydration and showed a Ca(2+) gradient, similar to the tip of growing pollen tubes. The same protocol can be used with the AM-forms of other fluorescent dyes for effective labeling. When loading BCECF-AM into pollen at high temperature, the pollen did not show a pH gradient after hydration. Ca(2+) activities and fluxes had the same periodicity as pollen germination, but pH did not show the same phase and mostly lagged behind. However, the clear zone was alkaline when pollen tube growth was slowed or stopped and turned acidic when growth recovered. It is likely that apical pH(i) regulated pollen tube growth.
Collapse
Affiliation(s)
- Haiyong Qu
- College of Horticulture, Nanjing Agricultural University, No.1. WeiGang, Nanjing, Jiangsu, China.
| | | | | | | | | |
Collapse
|
30
|
Brownlee C, Hetherington A. Introduction to a Virtual Special Issue on calcium signalling in plants. THE NEW PHYTOLOGIST 2011; 192:786-789. [PMID: 22074334 DOI: 10.1111/j.1469-8137.2011.03964.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
|
31
|
Bou Daher F, Geitmann A. Actin is Involved in Pollen Tube Tropism Through Redefining the Spatial Targeting of Secretory Vesicles. Traffic 2011; 12:1537-51. [DOI: 10.1111/j.1600-0854.2011.01256.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
32
|
Wu J, Qu H, Jin C, Shang Z, Wu J, Xu G, Gao Y, Zhang S. cAMP activates hyperpolarization-activated Ca2+ channels in the pollen of Pyrus pyrifolia. PLANT CELL REPORTS 2011; 30:1193-1200. [PMID: 21331543 DOI: 10.1007/s00299-011-1027-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Revised: 01/23/2011] [Accepted: 01/25/2011] [Indexed: 05/30/2023]
Abstract
Many signal-transduction processes in plant cells have been suggested to be triggered by signal-induced opening of calcium ion (Ca(2+)) channels in the plasma membrane. Cyclic nucleotides have been proposed to lead to an increase in cytosolic free Ca(2+) in pollen. However, direct recordings of cyclic-nucleotide-induced Ca(2+) currents in pollen have not yet been obtained. Here, we report that cyclic AMP (cAMP) activated a hyperpolarization-activated Ca(2+) channel in the Pyrus pyrifolia pollen tube using the patch-clamp technique, which resulted in a significant increase in pollen tube protoplast cytosolic-Ca(2+) concentration. Outside-out single channel configuration identified that cAMP directly increased the Ca(2+) channel open-probability without affecting channel conductance. cAMP-induced currents were composed of both Ca(2+) and K(+). However, cGMP failed to mimic the cAMP effect. Higher cytosolic free-Ca(2+) concentration significantly decreased the cAMP-induced currents. These results provide direct evidence for cAMP activation of hyperpolarization-activated Ca(2+) channels in the plasma membrane of pollen tubes, which, in turn, modulate cellular responses in regulation of pollen tube growth.
Collapse
Affiliation(s)
- Juyou Wu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, No. 6 Tongwei Road, Nanjing, China
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Michard E, Lima PT, Borges F, Silva AC, Portes MT, Carvalho JE, Gilliham M, Liu LH, Obermeyer G, Feijó JA. Glutamate receptor-like genes form Ca2+ channels in pollen tubes and are regulated by pistil D-serine. Science 2011; 332:434-7. [PMID: 21415319 DOI: 10.1126/science.1201101] [Citation(s) in RCA: 273] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Elevations in cytosolic free calcium concentration ([Ca(2+)](cyt)) constitute a fundamental signal transduction mechanism in eukaryotic cells, but the molecular identity of Ca(2+) channels initiating this signal in plants is still under debate. Here, we show by pharmacology and loss-of-function mutants that in tobacco and Arabidopsis, glutamate receptor-like channels (GLRs) facilitate Ca(2+) influx across the plasma membrane, modulate apical [Ca(2+)](cyt) gradient, and consequently affect pollen tube growth and morphogenesis. Additionally, wild-type pollen tubes grown in pistils of knock-out mutants for serine-racemase (SR1) displayed growth defects consistent with a decrease in GLR activity. Our findings reveal a novel plant signaling mechanism between male gametophyte and pistil tissue similar to amino acid-mediated communication commonly observed in animal nervous systems.
Collapse
Affiliation(s)
- Erwan Michard
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, P-2780-156 Oeiras, Portugal
| | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Tavares B, Domingos P, Dias PN, Feijó JA, Bicho A. The essential role of anionic transport in plant cells: the pollen tube as a case study. JOURNAL OF EXPERIMENTAL BOTANY 2011; 62:2273-2298. [PMID: 21511914 DOI: 10.1093/jxb/err036] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Plasma membrane anion transporters play fundamental roles in plant cell biology, especially in stomatal closure and nutrition. Notwithstanding, a lot is still unknown about the specific function of these transporters, their specific localization, or molecular nature. Here the fundamental roles of anionic transport in plant cells are reviewed. Special attention will be paid to them in the control of pollen tube growth. Pollen tubes are extreme examples of cellular polarity as they grow exclusively in their apical extremity. Their unique cell biology has been extensively exploited for fundamental understanding of cellular growth and morphogenesis. Non-invasive methods have demonstrated that tube growth is governed by different ion fluxes, with different properties and distribution. Not much is known about the nature of the membrane transporters responsible for anionic transport and their regulation in the pollen tube. Recent data indicate the importance of chloride (Cl(-)) transfer across the plasma membrane for pollen germination and pollen tube growth. A general overview is presented of the well-known accumulated data in terms of biophysical and functional characterization, transcriptomics, and genomic description of pollen ionic transport, and the various controversies around the role of anionic fluxes during pollen tube germination, growth, and development. It is concluded that, like all other plant cells so far analysed, pollen tubes depend on anion fluxes for a number of fundamental homeostatic properties.
Collapse
|
35
|
Wu JY, Qu HY, Shang ZL, Tao ST, Xu GH, Wu J, Wu HQ, Zhang SL. Reciprocal regulation of Ca²+-activated outward K+ channels of Pyrus pyrifolia pollen by heme and carbon monoxide. THE NEW PHYTOLOGIST 2011; 189:1060-1068. [PMID: 21133925 DOI: 10.1111/j.1469-8137.2010.03564.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
• The regulation of plant potassium (K+) channels has been extensively studied in various systems. However, the mechanism of their regulation in the pollen tube is unclear. • In this study, the effects of heme and carbon monoxide (CO) on the outward K+ (K+(out)) channel in pear (Pyrus pyrifolia) pollen tube protoplasts were characterized using a patch-clamp technique. • Heme (1 μM) decreased the probability of K+(out) channel opening without affecting the unitary conductance, but this inhibition disappeared when heme was co-applied with 10 μM intracellular free Ca²+. Conversely, exposure to heme in the presence of NADPH increased channel activity. However, with tin protoporphyrin IX treatment, which inhibits hemeoxygenase activity, the inhibition of the K+(out) channel by heme occurred even in the presence of NADPH. CO, a product of heme catabolism by hemeoxygenase, activates the K+(out) channel in pollen tube protoplasts in a dose-dependent manner. The current induced by CO was inhibited by the K+ channel inhibitor tetraethylammonium. • These data indicate a role of heme and CO in reciprocal regulation of the K+(out) channel in pear pollen tubes.
Collapse
Affiliation(s)
- Ju-You Wu
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Hai-Yong Qu
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Zhong-Lin Shang
- College of Life Sciences, HeBei Normal University, Shi Jia Zhuang 050016, China
| | - Shu-Tian Tao
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Guo-Hua Xu
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Jun Wu
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Hua-Qing Wu
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Shao-Ling Zhang
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| |
Collapse
|
36
|
Wu J, Wang S, Gu Y, Zhang S, Publicover SJ, Franklin-Tong VE. Self-incompatibility in Papaver rhoeas activates nonspecific cation conductance permeable to Ca2+ and K+. PLANT PHYSIOLOGY 2011; 155:963-73. [PMID: 21177472 PMCID: PMC3032480 DOI: 10.1104/pp.110.161927] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Accepted: 12/15/2010] [Indexed: 05/21/2023]
Abstract
Cellular responses rely on signaling. In plant cells, cytosolic free calcium is a major second messenger, and ion channels play a key role in mediating physiological responses. Self-incompatibility (SI) is an important genetically controlled mechanism to prevent self-fertilization. It uses interaction of matching S-determinants from the pistil and pollen to allow "self" recognition, which triggers rejection of incompatible pollen. In Papaver rhoeas, the S-determinants are PrsS and PrpS. PrsS is a small novel cysteine-rich protein; PrpS is a small novel transmembrane protein. Interaction of PrsS with incompatible pollen stimulates S-specific increases in cytosolic free calcium and alterations in the actin cytoskeleton, resulting in programmed cell death in incompatible but not compatible pollen. Here, we have used whole-cell patch clamping of pollen protoplasts to show that PrsS stimulates SI-specific activation of pollen grain plasma membrane conductance in incompatible but not compatible pollen grain protoplasts. The SI-activated conductance does not require voltage activation, but it is voltage sensitive. It is permeable to divalent cations (Ba(2+) ≥ Ca(2+) > Mg(2+)) and the monovalent ions K(+) and NH(4)(+) and is enhanced at voltages negative to -100 mV. The Ca(2+) conductance is blocked by La(3+) but not by verapamil; the K(+) currents are tetraethylammonium chloride insensitive and do not require Ca(2+). We propose that the SI-stimulated conductance may represent a nonspecific cation channel or possibly two conductances, permeable to monovalent and divalent cations. Our data provide insights into signal-response coupling involving a biologically important response. PrsS provides a rare example of a protein triggering alterations in ion channel activity.
Collapse
|
37
|
Abstract
Sodium (Na) toxicity is one of the most formidable challenges for crop production world-wide. Nevertheless, despite decades of intensive research, the pathways of Na(+) entry into the roots of plants under high salinity are still not definitively known. Here, we review critically the current paradigms in this field. In particular, we explore the evidence supporting the role of nonselective cation channels, potassium transporters, and transporters from the HKT family in primary sodium influx into plant roots, and their possible roles elsewhere. We furthermore discuss the evidence for the roles of transporters from the NHX and SOS families in intracellular Na(+) partitioning and removal from the cytosol of root cells. We also review the literature on the physiology of Na(+) fluxes and cytosolic Na(+) concentrations in roots and invite critical interpretation of seminal published data in these areas. The main focus of the review is Na(+) transport in glycophytes, but reference is made to literature on halophytes where it is essential to the analysis.
Collapse
|
38
|
Wang CL, Wu J, Xu GH, Gao YB, Chen G, Wu JY, Wu HQ, Zhang SL. S-RNase disrupts tip-localized reactive oxygen species and induces nuclear DNA degradation in incompatible pollen tubes of Pyrus pyrifolia. J Cell Sci 2010; 123:4301-9. [PMID: 21098637 DOI: 10.1242/jcs.075077] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pear (Pyrus pyrifolia L.) has an S-RNase-based gametophytic self-incompatibility (SI) mechanism, and S-RNase has also been implicated in the rejection of self-pollen and genetically identical pollen. However, RNA degradation might be only the beginning of the SI response, not the end. Recent in vitro studies suggest that S-RNase triggers mitochondrial alteration and DNA degradation in the incompatible pollen tube of Pyrus pyrifolia, and it seems that a relationship exists between self S-RNase, actin depolymerization and DNA degradation. To further uncover the SI response in pear, the relationship between self S-RNase and tip-localized reactive oxygen species (ROS) was evaluated. Our results show that S-RNase specifically disrupted tip-localized ROS of incompatible pollen tubes via arrest of ROS formation in mitochondria and cell walls. The mitochondrial ROS disruption was related to mitochondrial alteration, whereas cell wall ROS disruption was related to a decrease in NADPH. Tip-localized ROS disruption not only decreased the Ca(2+) current and depolymerized the actin cytoskeleton, but it also induced nuclear DNA degradation. These results indicate that tip-localized ROS disruption occurs in Pyrus pyrifolia SI. Importantly, we demonstrated nuclear DNA degradation in the incompatible pollen tube after pollination in vivo. This result validates our in vitro system in vivo.
Collapse
Affiliation(s)
- Chun-Lei Wang
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | | | | | | | | | | | | | | |
Collapse
|
39
|
Hsu SW, Wang CS. Lily Cdc42/Rac-interactive binding motif-containing protein, a Rop target, involves calcium influx and phosphoproteins during pollen germination and tube growth. PLANT SIGNALING & BEHAVIOR 2010; 5:1460-3. [PMID: 21060254 PMCID: PMC3115255 DOI: 10.4161/psb.5.11.13466] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Accepted: 08/27/2010] [Indexed: 05/25/2023]
Abstract
We report unique desiccation-associated ABA signaling transduction through which the Rop (Rho GTPase of plants) and its target LLP12-2 are regulated during the stage of pollen maturation and tube growth. Overexpression of LLP12-2 drastically inhibited pollen germination and tube growth. Studies on the germination inhibitors, Ca (2+) influx blocking agents LaCl 3 and EGTA and an actin-depolymerizing drug, latrunculin B (LatB), revealed that the LLP12-2-induced inhibition of germination and tube growth is significantly suppressed by LaCl 3 and EGTA in the LLP12-2-overexpressing pollen but not by LatB. These results suggested that LLP12-2 is associated with Ca (2+) influx in the cytoplasm and may be not with actin assembly. With the addition of LaCl 3 and EGTA, LLP12-2-overexpressing pollen increased germination and tube growth compared with the one without addition, whereas pollen expressing GFP decreased germination and tube growth. Thus, an optimum level of [Ca (2+) ]cyt influx is crucial for normal germination and tube growth. Studies on the inhibitors, staurosporine and okadaic acid in the LLP12-2-overexpressing pollen, showed no appreciable increase in germination when compared with the one without addition, suggesting that staurosporine-sensitive protein kinases and dephosphorylation of phosphoproteins may be not involved in the LLP12-2 mediated germination. However, the LLP12-2-induced inhibition of tube length was slightly but significantly suppressed by staurosporine, suggesting that staurosporine-sensitive protein kinases involve in the LLP12-2-induced inhibition of tube growth.
Collapse
Affiliation(s)
- Ssu-Wei Hsu
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan
| | | |
Collapse
|
40
|
Wu J, Shang Z, Wu J, Jiang X, Moschou PN, Sun W, Roubelakis-Angelakis KA, Zhang S. Spermidine oxidase-derived H₂O₂ regulates pollen plasma membrane hyperpolarization-activated Ca(2+) -permeable channels and pollen tube growth. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 63:1042-53. [PMID: 20626657 DOI: 10.1111/j.1365-313x.2010.04301.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Spermidine (Spd) has been correlated with various physiological and developmental processes in plants, including pollen tube growth. In this work, we show that Spd induces an increase in the cytosolic Ca(2+) concentration that accompanies pollen tube growth. Using the whole-cell patch clamp and outside-out single-channel patch clamp configurations, we show that exogenous Spd induces a hyperpolarization-activated Ca(2+) current: the addition of Spd cannot induce the channel open probability increase in excised outside-out patches, indicating that the effect of Spd in the induction of Ca(2+) currents is exerted via a second messenger. This messenger is hydrogen peroxide (H₂O₂), and is generated during Spd oxidation, a reaction mediated by polyamine oxidase (PAO). These reactive oxygen species trigger the opening of the hyperpolarization-activated Ca(2+) -permeable channels in pollen. To provide further evidence that PAO is in fact responsible for the effect of Spd on the Ca(2+) -permeable channels, two Arabidopsis mutants lacking expression of the peroxisomal-encoding AtPAO3 gene, were isolated and characterized. Pollen from these mutants was unable to induce the opening of the Ca(2+) -permeable channels in the presence of Spd, resulting in reduced pollen tube growth and seed number. However, a high Spd concentration triggers a Ca(2+) influx beyond the optimal, which has a deleterious effect. These findings strongly suggest that the Spd-derived H₂O₂ signals Ca(2+) influx, thereby regulating pollen tube growth.
Collapse
Affiliation(s)
- Juyou Wu
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | | | | | | | | | | | | | | |
Collapse
|
41
|
Rincón-Zachary M, Teaster ND, Sparks JA, Valster AH, Motes CM, Blancaflor EB. Fluorescence resonance energy transfer-sensitized emission of yellow cameleon 3.60 reveals root zone-specific calcium signatures in Arabidopsis in response to aluminum and other trivalent cations. PLANT PHYSIOLOGY 2010; 152:1442-58. [PMID: 20053711 PMCID: PMC2832233 DOI: 10.1104/pp.109.147256] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Accepted: 01/03/2010] [Indexed: 05/02/2023]
Abstract
Fluorescence resonance energy transfer-sensitized emission of the yellow cameleon 3.60 was used to study the dynamics of cytoplasmic calcium ([Ca(2+)](cyt)) in different zones of living Arabidopsis (Arabidopsis thaliana) roots. Transient elevations of [Ca(2+)](cyt) were observed in response to glutamic acid (Glu), ATP, and aluminum (Al(3+)). Each chemical induced a [Ca(2+)](cyt) signature that differed among the three treatments in regard to the onset, duration, and shape of the response. Glu and ATP triggered patterns of [Ca(2+)](cyt) increases that were similar among the different root zones, whereas Al(3+) evoked [Ca(2+)](cyt) transients that had monophasic and biphasic shapes, most notably in the root transition zone. The Al(3+)-induced [Ca(2+)](cyt) increases generally started in the maturation zone and propagated toward the cap, while the earliest [Ca(2+)](cyt) response after Glu or ATP treatment occurred in an area that encompassed the meristem and elongation zone. The biphasic [Ca(2+)](cyt) signature resulting from Al(3+) treatment originated mostly from cortical cells located at 300 to 500 mu m from the root tip, which could be triggered in part through ligand-gated Glu receptors. Lanthanum and gadolinium, cations commonly used as Ca(2+) channel blockers, elicited [Ca(2+)](cyt) responses similar to those induced by Al(3+). The trivalent ion-induced [Ca(2+)](cyt) signatures in roots of an Al(3+)-resistant and an Al(3+)-sensitive mutant were similar to those of wild-type plants, indicating that the early [Ca(2+)](cyt) changes we report here may not be tightly linked to Al(3+) toxicity but rather to a general response to trivalent cations.
Collapse
Affiliation(s)
- Magaly Rincón-Zachary
- Department of Biology, College of Science and Mathematics, Midwestern State University, Wichita Falls, Texas 76308, USA.
| | | | | | | | | | | |
Collapse
|
42
|
Laohavisit A, Davies JM. Ion Channels in Plant Development. ION CHANNELS AND PLANT STRESS RESPONSES 2010. [DOI: 10.1007/978-3-642-10494-7_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
43
|
Pertl H, Schulze WX, Obermeyer G. The Pollen Organelle Membrane Proteome Reveals Highly Spatial−Temporal Dynamics during Germination and Tube Growth of Lily Pollen. J Proteome Res 2009; 8:5142-52. [DOI: 10.1021/pr900503f] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Heidi Pertl
- Molecular Plant Biophysics and Biochemistry, Deptartment of Molecular Biology, University of Salzburg, Billrothstrasse 11, 5020 Salzburg, Austria, and Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Golm, Germany
| | - Waltraud X. Schulze
- Molecular Plant Biophysics and Biochemistry, Deptartment of Molecular Biology, University of Salzburg, Billrothstrasse 11, 5020 Salzburg, Austria, and Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Golm, Germany
| | - Gerhard Obermeyer
- Molecular Plant Biophysics and Biochemistry, Deptartment of Molecular Biology, University of Salzburg, Billrothstrasse 11, 5020 Salzburg, Austria, and Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Golm, Germany
| |
Collapse
|
44
|
Snider JL, Oosterhuis DM, Skulman BW, Kawakami EM. Heat stress-induced limitations to reproductive success in Gossypium hirsutum. PHYSIOLOGIA PLANTARUM 2009; 137:125-38. [PMID: 19656331 DOI: 10.1111/j.1399-3054.2009.01266.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Using in vitro systems, numerous authors have cited the sensitivity of pollen tube growth to high temperature as a major cause of low yields for crops with valuable reproductive structures. We investigated the hypothesis that in vivo fertilization efficiency would be negatively affected by heat stress-induced changes in energy reserves and calcium-mediated oxidative status in the pistil. Gossypium hirsutum plants exposed to optimal (30/20 degrees C) or high day temperature (38/20 degrees C) conditions during flowering were analyzed for fertilization efficiency via UV microscopic observation of pollen tube-containing ovules and for soluble carbohydrates, adenosine triphosphate (ATP), calcium, antioxidant enzyme activity and NADPH oxidase (NOX; EC 1.6.3.1) activity in the pistil. Leaf measurements included gas exchange, chlorophyll content, quantum efficiency and ATP content of the subtending leaf on the day of anthesis. In the pistil fertilization efficiency, soluble carbohydrates, ATP content and NOX activity declined significantly, whereas water soluble calcium and glutathione reductase (EC 1.8.1.7) activity increased, and superoxide dismutase (EC 1.15.1.1) activity remained unchanged. In leaves, heat stress decreased photosynthesis, quantum efficiency and chlorophyll content, but increased stomatal conductance. We conclude that decreased source leaf activity either inhibits pollen development, tube growth through the style or guidance to the ovules as a result of an insufficient energy supply to the developing pistil. We further conclude that a calcium-augmented antioxidant response in heat-stressed pistils interferes with enzymatic superoxide production needed for normal pollen tube growth and fertilization of the ovule.
Collapse
Affiliation(s)
- John L Snider
- Department of Crop, Soil, and Environmental Sciences, University of Arkansas, Fayetteville, AR 72704, USA.
| | | | | | | |
Collapse
|
45
|
Wang CL, Xu GH, Jiang XT, Chen G, Wu J, Wu HQ, Zhang SL. S-RNase triggers mitochondrial alteration and DNA degradation in the incompatible pollen tube of Pyrus pyrifolia in vitro. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2009; 57:220-9. [PMID: 18786182 DOI: 10.1111/j.1365-313x.2008.03681.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Pear (Pyrus pyrifolia L.) has a S-RNase-based gametophytic self-incompatibility (SI) mechanism, and S-RNase has also been implicated in the rejection of self-pollen and genetically identical pollen. No studies, however, have examined the extent of organelle alterations during the SI response in Pyrus pyrifolia. Consequently, this study focused on the alterations to mitochondria and nuclear DNA in incompatible pollen tubes of the pear. Methylthiazolyldiphenyl-tetrazolium bromide was used to evaluate the viability of pollen tubes under S-RNase challenge. The results showed that the viability of the control and compatible pollen tubes decreased slightly, but that of the incompatible pollen and pollen tubes began to decline at 30 min. The mitochondrial membrane potential (Delta psi(mit)) was also tested with rhodamine 123 30 min after SI challenge, and was shown to have collapsed in the incompatible pollen tubes after exposure to S-RNase. Western blotting 2 h after SI challenge confirmed that the Delta psi(mit) collapse induced leakage of cytochrome c into the cytosol. Swollen mitochondria were detected by transmission electron microscopy as early as 1 h after SI challenge and the degradation of nuclear DNA was observed by both 4,6-diamidino-2-phenylindole and transferase-mediated dUTP nick-end labeling. These diagnostic features of programmed cell death (PCD) suggested that PCD may specifically occur in incompatible pollen tubes.
Collapse
Affiliation(s)
- Chun-Lei Wang
- Pear Engineering Research Center, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | | | | | | | | | | | | |
Collapse
|
46
|
Maresova L, Muend S, Zhang YQ, Sychrova H, Rao R. Membrane hyperpolarization drives cation influx and fungicidal activity of amiodarone. J Biol Chem 2008; 284:2795-2802. [PMID: 19054772 DOI: 10.1074/jbc.m806693200] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cationic amphipathic drugs, such as amiodarone, interact preferentially with lipid membranes to exert their biological effect. In the yeast Saccharomyces cerevisiae, toxic levels of amiodarone trigger a rapid influx of Ca(2+) that can overwhelm cellular homeostasis and lead to cell death. To better understand the mechanistic basis of antifungal activity, we assessed the effect of the drug on membrane potential. We show that low concentrations of amiodarone (0.1-2 microm) elicit an immediate, dose-dependent hyperpolarization of the membrane. At higher doses (>3 microm), hyperpolarization is transient and is followed by depolarization, coincident with influx of Ca(2+) and H(+) and loss in cell viability. Proton and alkali metal cation transporters play reciprocal roles in membrane polarization, depending on the availability of glucose. Diminishment of membrane potential by glucose removal or addition of salts or in pma1, tok1Delta, ena1-4Delta, or nha1Delta mutants protected against drug toxicity, suggesting that initial hyperpolarization was important in the mechanism of antifungal activity. Furthermore, we show that the link between membrane hyperpolarization and drug toxicity is pH-dependent. We propose the existence of pH- and hyperpolarization-activated Ca(2+) channels in yeast, similar to those described in plant root hair and pollen tubes that are critical for cell elongation and growth. Our findings illustrate how membrane-active compounds can be effective microbicidals and may pave the way to developing membrane-selective agents.
Collapse
Affiliation(s)
- Lydie Maresova
- Department of Membrane Transport, Institute of Physiology, Academy of Sciences CR, Prague, Czech Republic
| | - Sabina Muend
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Yong-Qiang Zhang
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Hana Sychrova
- Department of Membrane Transport, Institute of Physiology, Academy of Sciences CR, Prague, Czech Republic
| | - Rajini Rao
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
| |
Collapse
|
47
|
Cheung AY, Wu HM. Structural and signaling networks for the polar cell growth machinery in pollen tubes. ANNUAL REVIEW OF PLANT BIOLOGY 2008; 59:547-72. [PMID: 18444907 DOI: 10.1146/annurev.arplant.59.032607.092921] [Citation(s) in RCA: 188] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Pollen tubes elongate within the pistil to transport sperms to the female gametophytes for fertilization. Pollen tubes grow at their tips through a rapid and polarized cell growth process. This tip growth process is supported by an elaborate and dynamic actin cytoskeleton and a highly active membrane trafficking system that together provide the driving force and secretory activities needed for growth. A polarized cytoplasm with an abundance of vesicles and tip-focused Ca(2+) and H(+) concentration gradients are important for the polar cell growth process. Apical membrane-located Rho GTPases regulate Ca(2+) concentration and actin dynamics in the cytoplasm and are crucial for maintaining pollen tube polarity. Pollen tube growth is marked by periods of rapid and slow growth phases. Activities that regulate and support this tip growth process also show oscillatory fluctuations. How these activities correlate with the rapid, polar, and oscillatory pollen tube growth process is discussed.
Collapse
Affiliation(s)
- Alice Y Cheung
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003, USA.
| | | |
Collapse
|
48
|
Wu Y, Xu X, Li S, Liu T, Ma L, Shang Z. Heterotrimeric G-protein participation in Arabidopsis pollen germination through modulation of a plasmamembrane hyperpolarization-activated Ca2+-permeable channel. THE NEW PHYTOLOGIST 2007; 176:550-559. [PMID: 17953540 DOI: 10.1111/j.1469-8137.2007.02214.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The role of heterotrimeric G proteins in pollen germination and tube growth was investigated using Arabidopsis thaliana plants in which the gene (GPA) encoding the G-protein a subunit (Galpha) was null or overexpressed. Pollen germination, free cytosolic calcium concentration ([Ca(2+)](cyt)) and Ca(2+) channel activity in the plasma membrane (PM) of pollen cells were investigated. Results showed that, compared with pollen grains of the wild type (ecotype Wassilewskija, ws), in vitro germinated pollen of Galpha null mutants (gpa1-1 and gpa1-2) had lower germination percentages and shorter pollen tubes, while pollen from Galpha overexpression lines (wGalpha and cGalpha) had higher germination percentages and longer pollen tubes. Compared with ws pollen cells, [Ca(2+)](cyt) was lower in gpa1-1 and gpa1-2 and higher in wGalpha and cGalpha. In whole-cell patch clamp recordings, a hyperpolarization-activated Ca(2+)-permeable conductance was identified in the PM of pollen protoplasts. The conductance was suppressed by trivalent cations but insensitive to organic blockers; its permeability to divalent cations was Ba(2+) > Ca(2+) > Mg(2+) > Sr(2+) > Mn(2+). The activity of the Ca(2+)-permeable channel conductance was down-regulated in pollen protoplasts of gpa1-1 and gpa1-2, and up-regulated in wGalpha and cGalpha. The results suggest that Galpha may participate in pollen germination through modulation of the hyperpolarization-activated Ca(2+) channel in the PM of pollen cells.
Collapse
Affiliation(s)
- Yansheng Wu
- College of Life Science, Hebei Normal University, Shijiazhuang 050016, China
| | - Xiaodong Xu
- College of Life Science, Hebei Normal University, Shijiazhuang 050016, China
| | - Sujuan Li
- College of Life Science, Hebei Normal University, Shijiazhuang 050016, China
| | - Ting Liu
- College of Life Science, Hebei Normal University, Shijiazhuang 050016, China
| | - Ligeng Ma
- College of Life Science, Hebei Normal University, Shijiazhuang 050016, China
| | - Zhonglin Shang
- College of Life Science, Hebei Normal University, Shijiazhuang 050016, China
| |
Collapse
|