Rice Genetics IV - IRRI books - International Rice Research Institute

Table 2. Abundance profile of expressed sequence tags (ESTs) in a root cDNA library of saltstressedmaize.Gene category No. % Category descriptionof ESTs of totalNo hit a 493 26.2 Blast search in nonredundant databases finds nohomologous sequencesUnknown b 296 15.7 Blast search in databases identifies unknown,hypothetical, and putative protein, or proteinswith unknown functionsMetabolism 203 10.8 Amino acid, nucleotide, C-compound, carbohydrate,lipid, fatty-acid, isoprenoid, nitrogen,sulfur, and secondary metabolismsCell rescue and defense 165 8.8 Environmental stimuli responses (stress-, wounding-,phytohormone-regulated, ion deficiencyrelated),radical oxygen scavenging, detoxification,DNA repair, and cell deathProtein synthesis 123 6.5 Ribosomal proteins, translation (initiation, elongation,and termination), translational control, andtRNA synthetasesEnergy 111 5.9 Glycolysis and gluconeogenesis, pentose-phosphatepathway, TCA pathway, respiration, metabolismof energy reserves (e.g., glycogen,trehalose), and fatty-acid oxidationTransport facilitation 76 4.0 Ion channels, water channels, ion, sugar, carbohydrate,amino acid, lipid, purine, pyrimidinetransporters, transport ATPasesProtein destination 76 4.0 Protein folding and stabilization, protein targeting,sorting, and translocation, protein modification(e.g., myristylation, farnesylation, palmitoylation,glycosylation), and proteolysisSignal transduction 75 4.0 (Putative) receptor proteins, second messengersuch as calmodulins, key kinases, key phosphatases,phospholipases, and G-proteinsCell growth, division 74 3.9 Cell growth and development, cell cycle control andmitosis, cytokinesis, and DNA synthesis andreplicationTranscription 71 3.8 mRNA synthesis (including general transcriptionactivities, transcriptional control such as transcriptionalfactors, and chromatin modification),mRNA splicing, and mRNA stabilization anddegradationPhotosynthesis 63 3.3 Chlorophyll a/b-binding protein, ferredoxin-relatedgenes, photosystem I & II reaction center proteinsMetal ion homeostasis 39 2.1 Homeostasis of metal ions and other ionsIntracellular transport 17 0.9 Vesicular transport (Golgi network), vacuolartransport, cytoskeleton-dependent transportTotal 1,882 100aNo significant homology with ESTs, cDNAs, or genes deposited in GenBank. b Significant homology withentries in GenBank for which no clear function is available.350 Bohnert et al