Table 2.
List of differentially expressed proteins identified using MALDI-TOF/TOF-MS in magnesium (Mg)-deficient Citrus sinensis roots
| Spot no. a | Accession no. b | Protein identity | Organism | MW (kDa) | MP/SC | Score | Ratio c |
|---|---|---|---|---|---|---|---|
| Carbohydrate and energy metabolism | |||||||
| R85 | gi|255579310 | Pyruvate decarboxylase, putative | Ricinus communis | 65.33 | 11/99 | 204 | 0.062 |
| R95 | gi|332195235 | Phosphoglycerate kinase | Arabidopsis thaliana | 49.91 | 17/92 | 110 | 0.235 |
| R83 | gi|710400 | Pyruvate dehydrogenase E1 alpha subunit | A. thaliana | 43.00 | 16/93 | 56 | 3.440 |
| R38 | gi|951369 | Ferredoxin NADP reductase | Pisum sativum | 10.82 | 8/101 | 53 | 2.495 |
| R111 | gi|222356610 | ATPase alpha subunit, partial (mitochondrion) | Afrothismia gabonensis | 40.27 | 15/94 | 210 | 2.279 |
| R36 | gi|302835814 | Adenylate kinase | Volvox carteri f. nagariensis | 25.89 | 11/78 | 60 | 2.446 |
| R120 | gi|33149683 | Alcohol dehydrogenase | Dianthus caryophyllus | 41.23 | 8/101 | 287 | 2.764 |
| R84 | gi|327555177 | Beta-amylase 8 | Hordeum vulgare subsp. vulgare | 51.37 | 17/93 | 57 | 3.121 |
| R121 | gi|11066213 | Hexokinase | Citrus sinensis | 54.02 | 14/93 | 253 | 6.019 |
| Protein metabolism | |||||||
| R1 | gi|255584432 | Proteasome subunit alpha type, putative | R. communis | 25.99 | 11/97 | 190 | 100 |
| R11 | gi|255620897 | Zinc metalloprotease, putative | R. communis | 17.94 | 9/99 | 57 | 3.011 |
| R13 | gi|255543801 | Cysteine protease, putative | R. communis | 41.04 | 7/103 | 91 | 4.924 |
| R35 | gi|332006674 | Putative S9 tyrosyl aminopeptidase | A. thaliana | 81.26 | 12/97 | 73 | 100 |
| R57 | gi|332006104 | Eukaryotic translation initiation factor 3B-2 | A. thaliana | 82.12 | 16/93 | 56 | 2.402 |
| R34 | gi|806808 | Chaperonin precursor | P. sativum | 62.95 | 12/97 | 131 | 0.180 |
| R56 | gi|806808 | Chaperonin precursor | P. sativum | 62.95 | 19/90 | 232 | 0.439 |
| R2 | gi|124484511 | Alpha chain of nascent polypeptide associated complex | Nicotiana benthamiana | 21.91 | 10/47 | 215 | 0.089 |
| Stress responses | |||||||
| R14 | gi|23477636 | Grp94 (HSP) | Xerophyta viscosa | 92.90 | 24/84 | 240 | 2.990 |
| R70 | gi|227438123 | Disease resistance protein | Brassica rapa subsp. pekinensis | 81.89 | 19/90 | 57 | 3.881 |
| R53 | gi|399940 | Heat shock 70 kDa protein, mitochondrial | 72.49 | 25/84 | 330 | 0.319 | |
| R100 | gi|4028567 | Heat shock protein HSP26 | Triticum aestivum | 26.48 | 12/97 | 66 | 0.325 |
| Nucleic acid metabolism | |||||||
| R37 | gi|90403817 | RNA polymerase beta chain | Beaucarnea recurvata | 94.49 | 22/87 | 72 | 0.481 |
| R68 | gi|226528292 | Spliceosome RNA helicase BAT1 | Zea mays | 45.12 | 19/91 | 245 | 0.456 |
| R82 | gi|33945882 | Transcription factor homolog BTF3-like protein | Lotus japonicus | 17.85 | 11/98 | 242 | 0.272 |
| Cell wall and cytoskeleton metabolism | |||||||
| R55 | gi|255115691 | Actin 1 | Boehmeria nivea | 41.64 | 19/90 | 245 | 5.833 |
| R69 | gi|71386188 | Villin 3 | Medicago sativa | 20.31 | 5/104 | 123 | 3.134 |
| R101 | gi|225454452 | Tubulin gamma-1 chain | Vitis vinifera | 53.25 | 12/97 | 104 | 2.600 |
| Lipid metabolism | |||||||
| R54 | gi|1117793 | Lipoxygenase | Solanum tuberosum | 99.60 | 14/95 | 65 | 2.074 |
| R99 | gi|870726 | Biotin carboxylase subunit | Nicotiana tabacum | 58.35 | 28/80 | 419 | 0.289 |
| Other and unknown biological processes | |||||||
| R3 | gi|30017553 | Unknown protein, 5’-partial | Oryza sativa Japonica Grou | 10.38 | 5/104 | 46 | 2.086 |
| R12 | gi|296086893 | Unnamed protein product | Vitis vinifera | 9.09 | 7/101 | 55 | 0.278 |
MP/SC: Number of matched peptides/sequence coverage percentage; MW: Theoretical molecular weigh;
a: Spot number corresponds to the 2-DE gel in Figure 4.
b: gi number is from NCBI database of matched protein.
c: Ratio means the ratio of Mg-deficiency to control; 0 means protein spots were only detected in control roots; 100 means protein spots were only detected in the Mg-deficient roots.