Welcome to Acta Agronomica Sinica，

Acta Agronomica Sinica ›› 2021, Vol. 47 ›› Issue (5): 814-826.doi: 10.3724/SP.J.1006.2021.04140

• CROP GENETICS & BREEDING·GERMPLASM RESOURCES·MOLECULAR GENETICS • Previous Articles     Next Articles

GhMADS7 positively regulates petal development in cotton

MA Huan-Huan(), FANG Qi-Di, DING Yuan-Hao, CHI Hua-Bin, ZHANG Xian-Long, MIN Ling*()   

  1. National Key Laboratory of Crop Genetic Improvement / College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
  • Received:2020-06-28 Accepted:2020-11-13 Online:2021-05-12 Published:2020-12-15
  • Contact: MIN Ling E-mail:1106825930@qq.com;lingmin@mail.hzau.edu.cn
  • Supported by:
    National Key Research and Development Program of China(2016YFD0101402)

RichHTML382

40

PDF

561

Abstract:

The MADS-box gene family, as an important class of transcription factors, is mainly involved in plant floral organs growth and development. GhMADS7/98 has a conserved MADS-box and K domain, belonging to the AG subgroup of MIKCC type MADS-box gene family. Through homology sequence alignment, GhMADS7/98 was 64% homologous to the Arabidopsis AGAMOUS (AG) gene. The GhMADS7 gene was expressed in petals, anthers, stigmas, and ovules, but with different temporal and spatial expression. To study the function of the gene, the RNA interference (RNAi) vector was constructed and transformed into cotton, and the transgenic lines with significantly reduced expression was obtained. These transgenic lines showed delayed petal development in the 5-6 mm and 7-8 mm buds. By observing the paraffin sections of the petals, it was found that vascular bundles in the petals of RNAi lines were shrived, compared with that in the wild type plants. To explore the reason, the expression of class A and B gene of ‘ABC’ model of floral development was detected in the petals by qRT-PCR, the result showed that the expression of most genes were upregulated in the RNAi plants, compared to WT. Therefore, it is speculated that GhMADS7 might cooperative with other petal development genes to regulate the cotton petal development.

Key words: cotton, MADS-box gene, GhMADS7, RNAi, petal development

Table 1

Sequence and purpose of the primers used in this study"

引物名称
Primer name		 引物序列
Primer sequence (5°-3°)		 用途
Purpose
ubiquitin7-F GAAGGCATTCCACCTGACCAAC 实时荧光定量PCR
ubiquitin7-R CTTGACCTTCTTCTTCTTGTGCTTG qRT-PCR
GhAMDS7-S TCATAGTTCAATTCCTTGCCAGC 基因扩增
GhAMDS7-A CTTGAATAGATGGAGGTGGAAGAGAG Gene amplification
OGhMADS7-F CCTTGCCAGCTTTGAACCAT 基因扩增
OGhMADS7-R ATGGAGGTGGAAGAGAGAAGCTAC Gene amplification
qGhMADS7-F AATGATTACTCCAACCAAGACCAA 实时荧光定量PCR
qGhMADS7-R TTGGTAGAACATTAGAGGCTGCTG qRT-PCR
bpGhMADS7-F GGGGACAAGTTTGTACAAAAAAGCAGGCTGGCCTTGCCAGCTTTGAACCAT BP反应
bpGhMADS7-R GGGGACCACTTTGTACAAGAAAGCTGGGTCATGGAGGTGGAAGAGAGAAGCTAC BP reaction
NPTII-F TTGTCACTGAAGCGGGAAGG 探针
NPTII-R CGATACCGTAAAGCACGAGGAA Probe

Fig. 1

Phylogenetic tree analysis of MIKCC MADS-box gene family in Gossypium hirsutum A: phylogenetic tree of MIKCC MADS-box gene family in Gossypium hirsutum; B: phylogenetic tree of AG subfamily of MIKCC MADS-box gene family in Gossypium hirsutum."

Fig. 2

Sequence analysis and tissue expression pattern analysis of GhMADS7 and GhMADS98 in Gossypium hirsutum A: alignment of the protein sequences of GhMADS7 and its homologous genes; B: the domain sequences analysis of GhMADS7; C: expression pattern analysis of GhMADS7 and GhMADS98 in Gossypium hirsutum. R: root; S: stem; L: leaf; P: petal; A: anther; S: stigma; O: ovule; F10 DPA/20 DPA: the fiber of 10 DPA/20 DPA; S10 DPA/20 DPA: the seed of 10 DPA/20 DPA."

Fig. 3

Expression pattern analysis of GhMADS7 in Gossypium hirsutum F<9: the length of flower bud is less than 9 mm; F9-14: the length of flower bud is 9-14 mm; F14-19: the length of flower bud is 14-19 mm; F>19: the length of flower bud is above 19 mm; F0: the flower bud on the day of flowering. The error bars represent deviations of three replicates. Significant differences in A, B, C, D were found by one-way ANOVA (P<0.05). Values with different letters are significantly different at P<0.05."

Fig. 4

Relative expression level of GhMADS7 RNAi in different transgenic lines and copy number of T-DNA in T0 transgenic lines A: relative expression level of GhMADS7 RNAi in different transgenic lines; B: copy number of T-DNA in T0 transgenic lines; YZ1: wild plant; iGhMADS7-3, iGhMADS7-17, iGhMADS7-20, iGhMADS7-27, iGhMADS7-32 represent five transgenic lines of GhMADS7 RNAi. The error bars represent deviations of three technical replicates."

Fig. 5

Phenotypic investigation of GhMADS7-RNAi transgenic plants 1-2 mm, 2-3 mm, 3-4 mm, 4-5 mm, 5-6 mm, 6-7 mm, and 7-8 mm represent the length of flower buds; Se: sepal; Pe: petal; Sti: stigma; Sta: stamen; Ca: carpel; Ov: ovule. Bar=500 µm (in WT and iGhMADS7-27)."

Fig. 6

Comparison of petal structure between GhMADS7-RNAi transgenic plants and wild type YZ1 by paraffin section iGhMADS7: suppression of GhMADS7 transgenic plants; YZ1: wild type plants. 2-3 mm to 7-8 mm represents the length of the bud. E1: epithelium cells; H1: hypodermic cells; Pt: thin-walled tissue; Vb: vascular bundle. 8, 10, 12 represent the cell layer number of the thin-walled tissue. Bar = 20 µm (in WT and iGhMADS7-27)."

Fig. 7

Relative expression levels of A and B type genes in GhMADS7 transgenic plants A: the expression levels of A genes in GhMADS7-RNAi transgenic plants; B: the expression levels of B genes in GhMADS7-RNAi transgenic plants. YZ1: wild type plant; iGhMADS7: suppression of GhMADS7 transgenic plant. F<5: the length of flower bud is less than 5 mm; F5-6: the length of flower bud is 5-6 mm; F6-7: the length of flower bud is 6-7 mm; F7-8: the length of flower bud is 7-8 mm; F8-9: the length of flower bud is 8-9 mm; F>9: the length of flower bud is above 9 mm. The error bars represent deviations of three replicates. *, ** mean significant differences at the 0.05 and 0.01 probability levels."

Fig. 8

Alignment of the protein sequences of GhMADS7, GhMADS3, and AtAG A: alignment of the protein sequences of GhMADS7 and ATAG; B: alignment of the protein sequences of GhMADS3 and AtAG."

Table S1

Gene ID of 76 MADS protein sequence for phylogenetic tree analysis"

基因号
ID		 基因名称
Name		 基因号
ID		 基因名称
Name		 基因号
ID		 基因名称
Name
Gh_D04G1849 GhMADS1 Gh_A08G1148 GhMADS45 Gh_D03G1493 GhMADS75
Gh_D05G2375 GhMADS2 Gh_A07G1339 GhMADS46 Gh_D10G0308 GhMADS76
Gh_A10G2220 GhMADS3 Gh_D08G1430 GhMADS47 Gh_D13G1226 GhMADS77
Gh_A10G2221 GhMADS4 Gh_A09G2157 GhMADS48 Gh_D11G0882 GhMADS78
Gh_D05G2596 GhMADS5 Gh_A04G1265 GhMADS49 Gh_D12G1000 GhMADS79
Gh_D04G0341 GhMADS7 Gh_A01G1608 GhMADS50 Gh_A04G1491 GhMADS80
Gh_A12G0910 GhMADS9 Gh_D03G0105 GhMADS51 Gh_D11G0883 GhMADS81
Gh_D10G0309 GhMDS10 Gh_D05G2452 GhMADS52 Gh_D12G1027 GhMADS82
Gh_D04G1892 GhMADS11 Gh_A05G2191 GhMADS53 Gh_D06G0245 GhMADS84
Gh_A02G0736 GhMADS12 Gh_D06G0267 GhMADS54 Gh_D11G3150 GhMADS85
Gh_A11G0754 GhMADS13 Gh_D02G2012 GhMADS55 Gh_D11G0082 GhMADS86
Gh_D12G2226 GhMADS14 Gh_A04G0934 GhMADS57 Gh_D02G0779 GhMADS87
Gh_A11G0077 GhMADS15 Gh_A12G0936 GhMADS58 Gh_A03G1085 GhMADS88
Gh_D02G1502 GhMADS16 Gh_A12G0570 GhMADS59 Gh_A07G0605 GhMADS89
Gh_D07G1814 GhMADS17 Gh_A11G0755 GhMADS60 Gh_A03G2004 GhMADS90
Gh_D13G0877 GhMADS20 Gh_D07G0780 GhMADS61 Gh_A12G2048 GhMADS91
Gh_D04G1451 GhMADS27 Gh_A07G1615 GhMADS62 Gh_A04G1264 GhMADS93
Gh_A13G0524 GhMADS28 Gh_A06G0244 GhMADS64 Gh_A13G0981 GhMADS94
Gh_D11G0400 GhMADS36 Gh_D13G0605 GhMADS66 Gh_A03G1563 GhMADS95
Gh_A06G1875 GhMADS37 Gh_A08G1275 GhMADS67 Gh_A12G0150 GhMADS96
Gh_D11G0534 GhMADS38 Gh_D12G0778 GhMADS68 Gh_A13G0425 GhMADS97
Gh_A12G0775 GhMADS40 Gh_D12G0163 GhMADS70 Gh_A05G3267 GhMADS98
Gh_A13G0751 GhMADS41 Gh_D09G2362 GhMADS71 Gh_A05G2136 GhMADS99
Gh_D04G1891 GhMADS42 Gh_D13G0878 GhMADS72 Gh_A05G2334 GhMADS100
Gh_A03G0634 GhMADS43 Gh_D07G0671 GhMADS73 Gh_Sca004768G07 GhMADS101
Gh_D02G1311 GhMADS44 Gh_D03G0922 GhMADS74 Gh_Sca007246G01 GhMADS102
[1] Coen E S, Meyerowitz E M. The war of the whorls: genetic interactions controlling flower development. Nature, 1991,353:31-37.
[2] Theien G. Development of floral organ identity: stories from the MADS house. Curr Opin Plant Biol, 2001,4:75-85.
[3] Alvarez-Buylla E R, Liljegren S J, Pelaz S, Gold S E, Ditta B C, Vergara-Silva F, Yanofsky M F. MADS-box gene evolution beyond flowers: expression in pollen, endosperm, guard cells, roots and trichomes. Plant J, 2000,24:457-466.
[4] Arora R, Agarwal P, Ray S, Singh A K, Singh V P, Tyagi A K, Kapoor S. MADS-box gene family in rice: genome-wide identification, organization and expression profiling during reproductive development and stress. BMC Genomics, 2007,8:242.
[5] Litt A, Irish V F. Duplication and diversification in the APETALA1/FRUITFULL floral homeotic gene lineage: implications for the evolution of floral development. Genetics, 2003,165:821-33.
[6] Svensson M. Evolution of a Family of Plant Genes with Regulatory Functions in Development; Studies on Picea abies and Lycopodium annotinum. PhD Dissertation of Uppsala University, Uppsala, Sweden, 2000.
[7] Smaczniak C, Immink R G, Angenent G C, Kaufmann K. Developmental and evolutionary diversity of plant MADS-domain factors: insights from recent studies. Development, 2012,139:3081-3098.
[8] José D R, Diego L, Martínez-Zapater J M, María José C. Genome-wide analysis of MIKCC-type MADS box genes in grapevine . Plant Physiol, 2009,149:354-369.
[9] Dreni L, Kater M M. MADS reloaded: evolution of the AGAMOUS subfamily genes. New Phytol, 2014,201:717-732.
[10] Gao Z H, Zhang Y M, Wang S, Zhang Z. Research progress in floral organ identity gene AGAMOUS. Acta Bot Boreali-Occident Sin, 2008,28:638-644.
[11] Jack T, Sieburth L, Meyerowitz E. Targeted misexpression of AGAMOUS in whorl 2 of Arabidopsis flowers. Plant J, 1997,11:825-839.
[12] Liu Z, Zhang D, Liu D, Li F, Lu H. Exon skipping of AGAMOUS homolog PrseAG in developing double flowers of Prunus lannesiana (Rosaceae). Plant Cell Rep, 2013,32:227-237.
[13] Hou J H, Gao Z H, Zhang Z, Chen S M, Ando T, Zhang J Y, Wang X W. Isolation and characterization of an AGAMOUS homologue pmAG from the Japanese Apricot ( Prunus mume Sieb. et Zucc.). Plant Mol Biol Rep, 2011,29:473-480.
[14] Junko K, Ko S. Ectopic expression of OsMADS3, a rice ortholog of AGAMOUS, caused a homeotic transformation of lodicules to stamens in transgenic rice plants. Plant Cell Physiol, 2002,43:130-135.
[15] Pnueli L. Isolation of the tomato AGAMOUS gene TAG1 and analysis of its homeotic role in transgenic plants. Plant Cell, 1994,6:163-173.
[16] Helliwell C A, Wesley S V, Wielopolska A J, Waterhouse P M. High-throughput vectors for efficient gene silencing in plants. Funct Plant Biol, 2002,29:1217-1225.
[17] Jin S X, Zhang X L, Liang S G, Nie Y C, Guo X P, Huang C. Factors affecting transformation efficiency of embryogenic callus of Upland cotton ( Gossypium hirsutum) with Agrobacterium tumefaciens. Plant Cell Tissue Organ Cult, 2005,81:229-237.
[18] Min L, Zhu L F, Tu L L, Deng F L, Yuan D J, Zhang X L. Cotton GhCKI disrupts normal male reproduction by delaying tapetum programmed cell death via inactivating starch synthase. Plant J, 2013,75:823-835.
[19] Ding Y H, Ma Y Z, Liu N, Xu J, Hu Q, Li Y Y, Xie S, Zhu L F, Min L, Zhang X L. microRNAs involved in auxin signalling modulate male sterility under high temperature stress in cotton ( Gossypium hirsutum). Plant J, 2017,91:977-994.
[20] Becker A, Winter K U, Meyer B, Saedler H, Theissen G. MADS-Box gene diversity in seed plants 300 million years ago. Mol Biol Evol, 2000,17:1425-1434.
[21] Zhang T Z, Hu Y, Jiang W K, Fang L, Guan X Y, Chen J D, Zhang J B, Christopher A S, Brian E S, David M S, Amanda M H K, Wan Q, Liu B L, Liu C X, Wang S, Pan M Q, Wang Y K, Wang D W, Ye W X, Chang L J, Zhang W P, Song Q X, Ryan C K, Chen X Y, Elizabeth D, Danny J L, Daniel G P, Peggy T, Don C J, Wang Q, Xu X Y, Zhang H, Wu H T, Zhou L, Mei G F, Chen S Q, Tian Y, Xiang D, Li X H, Ding J, Zuo Q Y, Tao L N, Liu Y C, Li J, Lin Y, Hui Y Y, Cao Z S, Cai C P, Zhu X F, Jiang Z, Zhou B L, Guo W Z, Li R Q, Chen Z J. Sequencing of allotetraploid cotton ( Gossypium hirsutum L. acc. TM-1) provides a resource for fiber improvement. Nat Biotechnol, 2015,33:531-537.
[22] Mizukami Y, Ma H. Ectopic expression of the floral homeotic gene AGAMOUS in transgenic Arabidopsis plants alters floral organ identity. Cell, 1992,71:119-131.
[23] 靳春梅, 周坤, 张今今. 茶树花发育MADS-box转录因子CsGLO1、CsGLO2与CsAG之间的互作关系研究. 植物科学学报, 2017,35(1):79-86.
Jin C M, Zhou K, Zhang J J. Interactions of MADS-box transcription factors CsGLO1, CsGLO2 and CsAG in Camellia sinensis flower development. Plant Sci J, 2017,35(1):79-86 (in Chinese with English abstract).
[24] 田亚然, 范天刚, 张钢, 李永红. 低温引起月季花朵过度重瓣化关键基因的表达及分析. 热带作物学报, 2016,37:1147-1154.
Tian Y R, Fan T G, Zhang G, Li Y H. Expression and analysis of key genes of excessive double flowers in rose caused by low temperature. Chin J Trop Crops, 2016,37:1147-1154 (in Chinese with English abstract).
[25] 陈之琳, 秦波, 蔡明, 郑唐春, 潘会堂, 王国熙, 潘隆应, 朱嫄, 张启翔. 大花紫薇B类和C类基因克隆及表达模式分析. 见: 张启翔主编. 中国观赏园艺研究进展2017. 北京: 中国林业出版社, 2017. pp 746-756.
Chen Z L, Qin B, Cai M, Zheng T C, Pan H T, Wang G X, Pan L Y, Zhu Y, Zhang Q X. Cloning and expression pattern analysis of B-function and C-function genes in Lagerstroemia speciosa. In: Zhang Q X, eds. Advances in Ornamental Horticulture of China (2017). Beijing: Chinese Forestry Publishing House, 2017. pp 746-756(in Chinese).
[26] 孙迎坤. 山茶花MADS-box家族A类和C类基因克隆及功能分析. 中国林业科学研究院博士学位论文, 北京, 2013.
Sun Y K. Isolation and Function Analysis of Class A and C Genes of MADS-box Family from Camellia japonica. PhD Dissertation of Chinese Academy of Forestry, Beijing, China, 2013 (in Chinese with English abstract).
[27] Narumi T, Aida R, Niki T, Nishijima T, Mitsuda N, Hiratsu K, Ohme-Takagi M, Ohtsubo N. Chimeric AGAMOUS repressor induces serrated petal phenotype in Torenia fournieri similar to that induced by cytokinin application. Jpn Soc Plant Cell Mol Biol, 2008,25:45-53.
[28] Guo Y L, Zhu Q L, Zheng S Y, Li M Y. Cloning of a MADS box gene ( GhMADS3) from cotton and analysis of its homeotic role in transgenic tobacco. J Genet Genomics, 2007,34:527-535.
[29] Yamaguchi T, Lee D Y, Miyao A, Hirochika H, An G, Hirano H Y. Functional diversification of the two C-class MADS box genes OSMADS3 and OSMADS58 in Oryza sativa. Plant Cell, 2006,18:15-28.
[30] Yun D P, Liang W Q, Dreni L, Yin C S, Zhou Z G, Kater M M, Zhang D B. OsMADS16 genetically interacts with OsMADS3 and OsMADS58 in specifying floral patterning in rice. Mol Plant, 2013,6:743-756.
[31] 段晓姗. 毛茛科C类MADS-Box基因的克隆和表达研究. 陕西师范大学硕士学位论文, 陕西西安, 2011.
Duan X S. Study on Cloning and Expression of C-type MADS-Box Gene in Ranunculaceae. MS Thesis of Shaanxi Normal University, Xi’an, Shaanxi, China, 2011 (in Chinese with English abstract).
[32] Kramer E M, Jaramillo M A, Stilio V S D. Patterns of gene duplication and functional evolution during the diversification of the AGAMOUS subfamily of MADS box genes in angiosperms. Genetics, 2004,166:1011-1023.
[1] ZHOU Jing-Yuan, KONG Xiang-Qiang, ZHANG Yan-Jun, LI Xue-Yuan, ZHANG Dong-Mei, DONG He-Zhong. Mechanism and technology of stand establishment improvements through regulating the apical hook formation and hypocotyl growth during seed germination and emergence in cotton [J]. Acta Agronomica Sinica, 2022, 48(5): 1051-1058.
[2] SUN Si-Min, HAN Bei, CHEN Lin, SUN Wei-Nan, ZHANG Xian-Long, YANG Xi-Yan. Root system architecture analysis and genome-wide association study of root system architecture related traits in cotton [J]. Acta Agronomica Sinica, 2022, 48(5): 1081-1090.
[3] YAN Xiao-Yu, GUO Wen-Jun, QIN Du-Lin, WANG Shuang-Lei, NIE Jun-Jun, ZHAO Na, QI Jie, SONG Xian-Liang, MAO Li-Li, SUN Xue-Zhen. Effects of cotton stubble return and subsoiling on dry matter accumulation, nutrient uptake, and yield of cotton in coastal saline-alkali soil [J]. Acta Agronomica Sinica, 2022, 48(5): 1235-1247.
[4] ZHENG Shu-Feng, LIU Xiao-Ling, WANG Wei, XU Dao-Qing, KAN Hua-Chun, CHEN Min, LI Shu-Ying. On the green and light-simplified and mechanized cultivation of cotton in a cotton-based double cropping system [J]. Acta Agronomica Sinica, 2022, 48(3): 541-552.
[5] ZHANG Yan-Bo, WANG Yuan, FENG Gan-Yu, DUAN Hui-Rong, LIU Hai-Ying. QTLs analysis of oil and three main fatty acid contents in cottonseeds [J]. Acta Agronomica Sinica, 2022, 48(2): 380-395.
[6] ZHANG Te, WANG Mi-Feng, ZHAO Qiang. Effects of DPC and nitrogen fertilizer through drip irrigation on growth and yield in cotton [J]. Acta Agronomica Sinica, 2022, 48(2): 396-409.
[7] ER Chen, LIN Tao, XIA Wen, ZHANG Hao, XU Gao-Yu, TANG Qiu-Xiang. Coupling effects of irrigation and nitrogen levels on yield, water distribution and nitrate nitrogen residue of machine-harvested cotton [J]. Acta Agronomica Sinica, 2022, 48(2): 497-510.
[8] ZHAO Wen-Qing, XU Wen-Zheng, YANG Liu-Yan, LIU Yu, ZHOU Zhi-Guo, WANG You-Hua. Different response of cotton leaves to heat stress is closely related to the night starch degradation [J]. Acta Agronomica Sinica, 2021, 47(9): 1680-1689.
[9] YUE Dan-Dan, HAN Bei, Abid Ullah, ZHANG Xian-Long, YANG Xi-Yan. Fungi diversity analysis of rhizosphere under drought conditions in cotton [J]. Acta Agronomica Sinica, 2021, 47(9): 1806-1815.
[10] ZENG Zi-Jun, ZENG Yu, YAN Lei, CHENG Jin, JIANG Cun-Cang. Effects of boron deficiency/toxicity on the growth and proline metabolism of cotton seedlings [J]. Acta Agronomica Sinica, 2021, 47(8): 1616-1623.
[11] GAO Lu, XU Wen-Liang. GhP4H2 encoding a prolyl-4-hydroxylase is involved in regulating cotton fiber development [J]. Acta Agronomica Sinica, 2021, 47(7): 1239-1247.
[12] XU Nai-Yin, ZHAO Su-Qin, ZHANG Fang, FU Xiao-Qiong, YANG Xiao-Ni, QIAO Yin-Tao, SUN Shi-Xian. Retrospective evaluation of cotton varieties nationally registered for the Northwest Inland cotton growing regions based on GYT biplot analysis [J]. Acta Agronomica Sinica, 2021, 47(4): 660-671.
[13] ZHOU Guan-Tong, LEI Jian-Feng, DAI Pei-Hong, LIU Chao, LI Yue, LIU Xiao-Dong. Efficient screening system of effective sgRNA for cotton CRISPR/Cas9 gene editing [J]. Acta Agronomica Sinica, 2021, 47(3): 427-437.
[14] HAN Bei, WANG Xu-Wen, LI Bao-Qi, YU Yu, TIAN Qin, YANG Xi-Yan. Association analysis of drought tolerance traits of upland cotton accessions (Gossypium hirsutum L.) [J]. Acta Agronomica Sinica, 2021, 47(3): 438-450.
[15] LU He-Quan, TANG Wei, LUO Zhen, KONG Xiang-Qiang, LI Zhen-Huai, XU Shi-Zhen, XIN Cheng-Song. Effects of commercial organic fertilizer substituting chemical fertilizer partially on soil nutrients, plant development, and yield in cotton [J]. Acta Agronomica Sinica, 2021, 47(12): 2511-2521.
Viewed
Full text


Abstract

Cited
  Shared   
  Discussed   
No Suggested Reading articles found!
Add: No. 80 Xueyuan South Rd, Beijing 100081, P. R. China E-mail: zwxb301@caas.cn
Supported by Beijing Magtech Co.Ltd