Published in J Biol Chem on January 01, 1999
Autophagy regulates lipid metabolism. Nature (2009) 13.33
Direct reprogramming of terminally differentiated mature B lymphocytes to pluripotency. Cell (2008) 10.68
p53 target genes sestrin1 and sestrin2 connect genotoxic stress and mTOR signaling. Cell (2008) 6.88
Physiological significance of a peripheral tissue circadian clock. Proc Natl Acad Sci U S A (2008) 5.94
Sterol regulatory element binding protein-1c is a major mediator of insulin action on the hepatic expression of glucokinase and lipogenesis-related genes. Proc Natl Acad Sci U S A (1999) 4.88
Vascular tumors in livers with targeted inactivation of the von Hippel-Lindau tumor suppressor. Proc Natl Acad Sci U S A (2001) 4.60
Regulation of circadian behaviour and metabolism by REV-ERB-α and REV-ERB-β. Nature (2012) 4.15
Hypoxia-inducible factor-2 (HIF-2) regulates hepatic erythropoietin in vivo. J Clin Invest (2007) 3.61
A conditional transposon-based insertional mutagenesis screen for genes associated with mouse hepatocellular carcinoma. Nat Biotechnol (2009) 3.44
Targeted inactivation of hepatic Abca1 causes profound hypoalphalipoproteinemia and kidney hypercatabolism of apoA-I. J Clin Invest (2005) 3.25
Insulin receptor functionally enhances multistage tumor progression and conveys intrinsic resistance to IGF-1R targeted therapy. Proc Natl Acad Sci U S A (2010) 3.16
Hepatic CB1 receptor is required for development of diet-induced steatosis, dyslipidemia, and insulin and leptin resistance in mice. J Clin Invest (2008) 3.13
Liver-specific disruption of PPARgamma in leptin-deficient mice improves fatty liver but aggravates diabetic phenotypes. J Clin Invest (2003) 3.09
Contact-dependent inhibition of EGFR signaling by Nf2/Merlin. J Cell Biol (2007) 2.89
Conditional gene targeting in mouse pancreatic ß-Cells: analysis of ectopic Cre transgene expression in the brain. Diabetes (2010) 2.80
Dual role of proapoptotic BAD in insulin secretion and beta cell survival. Nat Med (2008) 2.78
Molecular physiology of mammalian glucokinase. Cell Mol Life Sci (2009) 2.66
Deletion of PPARgamma in adipose tissues of mice protects against high fat diet-induced obesity and insulin resistance. Proc Natl Acad Sci U S A (2005) 2.60
Direct lineage conversion of terminally differentiated hepatocytes to functional neurons. Cell Stem Cell (2011) 2.49
Nutrient-sensing mechanisms and pathways. Nature (2015) 2.46
Liver-specific deletion of histone deacetylase 3 disrupts metabolic transcriptional networks. EMBO J (2008) 2.44
Phosphoenolpyruvate carboxykinase is necessary for the integration of hepatic energy metabolism. Mol Cell Biol (2000) 2.42
Failure to prolyl hydroxylate hypoxia-inducible factor alpha phenocopies VHL inactivation in vivo. EMBO J (2006) 2.41
Txnip balances metabolic and growth signaling via PTEN disulfide reduction. Proc Natl Acad Sci U S A (2008) 2.41
The role of insulin receptor substrate 2 in hypothalamic and beta cell function. J Clin Invest (2005) 2.40
GABAergic RIP-Cre neurons in the arcuate nucleus selectively regulate energy expenditure. Cell (2012) 2.34
Dysregulation of insulin receptor substrate 2 in beta cells and brain causes obesity and diabetes. J Clin Invest (2004) 2.34
Inactivation of the arylhydrocarbon receptor nuclear translocator (Arnt) suppresses von Hippel-Lindau disease-associated vascular tumors in mice. Mol Cell Biol (2005) 2.25
Prevention of steatosis by hepatic JNK1. Cell Metab (2009) 2.20
NAFLD, NASH and liver cancer. Nat Rev Gastroenterol Hepatol (2013) 2.20
Probing cell type-specific functions of Gi in vivo identifies GPCR regulators of insulin secretion. J Clin Invest (2007) 2.20
Complementary roles of IRS-1 and IRS-2 in the hepatic regulation of metabolism. J Clin Invest (2005) 2.14
Of mice and MEN1: Insulinomas in a conditional mouse knockout. Mol Cell Biol (2003) 2.12
Intestinal hypoxia-inducible transcription factors are essential for iron absorption following iron deficiency. Cell Metab (2009) 2.09
The role of JNK in the development of hepatocellular carcinoma. Genes Dev (2011) 2.07
Brain fatty acid synthase activates PPARalpha to maintain energy homeostasis. J Clin Invest (2007) 2.03
Tissue-specific role of glycogen synthase kinase 3beta in glucose homeostasis and insulin action. Mol Cell Biol (2008) 2.03
Epithelial-to-mesenchymal transitions in the liver. Hepatology (2009) 1.99
Deficient chaperone-mediated autophagy in liver leads to metabolic dysregulation. Cell Metab (2014) 1.98
Cre-mediated germline mosaicism: a method allowing rapid generation of several alleles of a target gene. Nucleic Acids Res (2000) 1.97
Compromised intestinal lipid absorption in mice with a liver-specific deficiency of liver receptor homolog 1. Mol Cell Biol (2007) 1.89
Hypoxia-inducible factor 2 regulates hepatic lipid metabolism. Mol Cell Biol (2009) 1.88
Energy metabolism in the liver. Compr Physiol (2014) 1.88
Disruption of Dicer1 induces dysregulated fetal gene expression and promotes hepatocarcinogenesis. Gastroenterology (2009) 1.86
Liver receptor homolog-1 regulates bile acid homeostasis but is not essential for feedback regulation of bile acid synthesis. Mol Endocrinol (2008) 1.85
Deletion of Smad2 in mouse liver reveals novel functions in hepatocyte growth and differentiation. Mol Cell Biol (2006) 1.82
Targeted deletion of Dicer from proximal tubules protects against renal ischemia-reperfusion injury. J Am Soc Nephrol (2010) 1.82
Aryl hydrocarbon receptor-dependent liver development and hepatotoxicity are mediated by different cell types. Proc Natl Acad Sci U S A (2005) 1.82
Induction of hepatitis by JNK-mediated expression of TNF-alpha. Cell (2009) 1.79
The MODY1 gene HNF-4alpha regulates selected genes involved in insulin secretion. J Clin Invest (2005) 1.78
Hepatocyte nuclear factor 3beta (Foxa2) is dispensable for maintaining the differentiated state of the adult hepatocyte. Mol Cell Biol (2000) 1.78
Hepatocyte-specific mutation establishes retinoid X receptor alpha as a heterodimeric integrator of multiple physiological processes in the liver. Mol Cell Biol (2000) 1.76
MTCH2/MIMP is a major facilitator of tBID recruitment to mitochondria. Nat Cell Biol (2010) 1.75
Essential role of STAT3 in body weight and glucose homeostasis. Mol Cell Biol (2004) 1.74
Insulin signaling is required for insulin's direct and indirect action on hepatic glucose production. J Clin Invest (2003) 1.73
Impaired adipogenesis and lipolysis in the mouse upon selective ablation of the retinoid X receptor alpha mediated by a tamoxifen-inducible chimeric Cre recombinase (Cre-ERT2) in adipocytes. Proc Natl Acad Sci U S A (2001) 1.69
pdx-1 function is specifically required in embryonic beta cells to generate appropriate numbers of endocrine cell types and maintain glucose homeostasis. Dev Biol (2007) 1.68
Tissue-specific deletion of Foxa2 in pancreatic beta cells results in hyperinsulinemic hypoglycemia. Genes Dev (2001) 1.67
MicroRNAs control hepatocyte proliferation during liver regeneration. Hepatology (2010) 1.64
The nuclear corepressor, NCoR, regulates thyroid hormone action in vivo. Proc Natl Acad Sci U S A (2008) 1.62
Alpha interferon induces long-lasting refractoriness of JAK-STAT signaling in the mouse liver through induction of USP18/UBP43. Mol Cell Biol (2009) 1.61
Phenotypic Characterization of MIP-CreERT1Lphi Mice With Transgene-Driven Islet Expression of Human Growth Hormone. Diabetes (2015) 1.59
Notch signaling regulates bile duct morphogenesis in mice. PLoS One (2008) 1.59
LRH-1-dependent glucose sensing determines intermediary metabolism in liver. J Clin Invest (2012) 1.58
Foxa2 regulates multiple pathways of insulin secretion. J Clin Invest (2004) 1.57
Deletion of the von Hippel-Lindau gene in pancreatic beta cells impairs glucose homeostasis in mice. J Clin Invest (2008) 1.56
No evidence for β cell neogenesis in murine adult pancreas. J Clin Invest (2013) 1.54
Circulating FGF21 is liver derived and enhances glucose uptake during refeeding and overfeeding. Diabetes (2014) 1.54
Casein kinase 1 delta regulates the pace of the mammalian circadian clock. Mol Cell Biol (2009) 1.52
Differential, type I interferon-mediated autophagic trafficking of hepatitis C virus proteins in mouse liver. Gastroenterology (2011) 1.52
Impaired insulin secretion and glucose tolerance in beta cell-selective Ca(v)1.2 Ca2+ channel null mice. EMBO J (2003) 1.51
Cytoprotective Nrf2 pathway is induced in chronically txnrd 1-deficient hepatocytes. PLoS One (2009) 1.50
Hepatitis B virus-induced lipid alterations contribute to natural killer T cell-dependent protective immunity. Nat Med (2012) 1.50
Phosphorylation of the nuclear receptor corepressor 1 by protein kinase B switches its corepressor targets in the liver in mice. Hepatology (2015) 1.49
Liver-specific deletion of augmenter of liver regeneration accelerates development of steatohepatitis and hepatocellular carcinoma in mice. Gastroenterology (2014) 1.48
Matricellular protein CCN1 promotes regression of liver fibrosis through induction of cellular senescence in hepatic myofibroblasts. Mol Cell Biol (2013) 1.47
GLUT4 glucose transporter deficiency increases hepatic lipid production and peripheral lipid utilization. J Clin Invest (2004) 1.47
Lack of protein S in mice causes embryonic lethal coagulopathy and vascular dysgenesis. J Clin Invest (2009) 1.47
Biphasic response of pancreatic beta-cell mass to ablation of tuberous sclerosis complex 2 in mice. Mol Cell Biol (2008) 1.46
Pancreas-specific Cre driver lines and considerations for their prudent use. Cell Metab (2013) 1.45
Erythropoietin protects against diabetes through direct effects on pancreatic beta cells. J Exp Med (2010) 1.44
Enteric neuron imbalance and proximal dysmotility in ganglionated intestine of the Sox10(Dom/+) Hirschsprung mouse model. Cell Mol Gastroenterol Hepatol (2015) 1.43
Loss of maternal Trim28 causes male-predominant early embryonic lethality. Genes Dev (2017) 1.40
Metabolic Adaptation Establishes Disease Tolerance to Sepsis. Cell (2017) 1.40
Zinc finger protein ZBTB20 is a key repressor of alpha-fetoprotein gene transcription in liver. Proc Natl Acad Sci U S A (2008) 1.38
Mice mutant for glucokinase regulatory protein exhibit decreased liver glucokinase: a sequestration mechanism in metabolic regulation. Proc Natl Acad Sci U S A (1999) 1.37
Frataxin deficiency in pancreatic islets causes diabetes due to loss of beta cell mass. J Clin Invest (2003) 1.37
Nkx6.1 controls a gene regulatory network required for establishing and maintaining pancreatic Beta cell identity. PLoS Genet (2013) 1.37
Concerted functions of Gab1 and Shp2 in liver regeneration and hepatoprotection. Mol Cell Biol (2006) 1.36
Muscle or liver-specific Sirt3 deficiency induces hyperacetylation of mitochondrial proteins without affecting global metabolic homeostasis. Sci Rep (2012) 1.35
Effects of GCK, GCKR, G6PC2 and MTNR1B variants on glucose metabolism and insulin secretion. PLoS One (2010) 1.33
Pulsatile portal vein insulin delivery enhances hepatic insulin action and signaling. Diabetes (2012) 1.32
Hepatocyte-derived Snail1 propagates liver fibrosis progression. Mol Cell Biol (2011) 1.32
Ptf1a binds to and activates area III, a highly conserved region of the Pdx1 promoter that mediates early pancreas-wide Pdx1 expression. Mol Cell Biol (2007) 1.31
IRE1α activation protects mice against acetaminophen-induced hepatotoxicity. J Exp Med (2012) 1.30
Conditional inactivation of the MEN1 gene leads to pancreatic and pituitary tumorigenesis but does not affect normal development of these tissues. Mol Cell Biol (2004) 1.29
A positive feedback loop between RIP3 and JNK controls non-alcoholic steatohepatitis. EMBO Mol Med (2014) 1.28
Bax and Bak function as the outer membrane component of the mitochondrial permeability pore in regulating necrotic cell death in mice. Elife (2013) 1.28
Ploidy reductions in murine fusion-derived hepatocytes. PLoS Genet (2009) 1.28
Key tissue targets responsible for anthrax-toxin-induced lethality. Nature (2013) 1.28
The Ensembl genome database project. Nucleic Acids Res (2002) 40.87
Gene-expression profiles in hereditary breast cancer. N Engl J Med (2001) 29.80
Ensembl 2009. Nucleic Acids Res (2008) 25.38
Role of AMP-activated protein kinase in mechanism of metformin action. J Clin Invest (2001) 23.21
Ensembl 2008. Nucleic Acids Res (2007) 20.67
Ensembl 2007. Nucleic Acids Res (2006) 20.10
Use of a cDNA microarray to analyse gene expression patterns in human cancer. Nat Genet (1996) 15.73
Molecular classification of cutaneous malignant melanoma by gene expression profiling. Nature (2000) 15.53
Ensembl 2005. Nucleic Acids Res (2005) 15.13
Allergic Rhinitis and its Impact on Asthma (ARIA) 2008 update (in collaboration with the World Health Organization, GA(2)LEN and AllerGen). Allergy (2008) 12.35
Ensembl 2002: accommodating comparative genomics. Nucleic Acids Res (2003) 12.26
Ensembl 2004. Nucleic Acids Res (2004) 11.88
Ensembl 2006. Nucleic Acids Res (2006) 11.66
Expression profiling using cDNA microarrays. Nat Genet (1999) 11.58
Origin of HIV-1 in the chimpanzee Pan troglodytes troglodytes. Nature (1999) 10.97
PDX-1 is required for pancreatic outgrowth and differentiation of the rostral duodenum. Development (1996) 9.58
Establishment of multiple sublineages of H5N1 influenza virus in Asia: implications for pandemic control. Proc Natl Acad Sci U S A (2006) 9.26
The combined functions of proapoptotic Bcl-2 family members bak and bax are essential for normal development of multiple tissues. Mol Cell (2000) 8.95
Data management and analysis for gene expression arrays. Nat Genet (1998) 8.60
Estrogen receptor status in breast cancer is associated with remarkably distinct gene expression patterns. Cancer Res (2001) 8.34
Ratio-based decisions and the quantitative analysis of cDNA microarray images. J Biomed Opt (1997) 8.32
Activation by IKKalpha of a second, evolutionary conserved, NF-kappa B signaling pathway. Science (2001) 7.66
Loss of insulin signaling in hepatocytes leads to severe insulin resistance and progressive hepatic dysfunction. Mol Cell (2000) 7.26
The genome of the natural genetic engineer Agrobacterium tumefaciens C58. Science (2001) 6.90
MicroRNA-34a functions as a potential tumor suppressor by inducing apoptosis in neuroblastoma cells. Oncogene (2007) 6.55
Tissue-specific knockout of the insulin receptor in pancreatic beta cells creates an insulin secretory defect similar to that in type 2 diabetes. Cell (1999) 6.53
Antagonism of central melanocortin receptors in vitro and in vivo by agouti-related protein. Science (1997) 6.23
Positive and negative regulation of IkappaB kinase activity through IKKbeta subunit phosphorylation. Science (1999) 5.95
Tissue-specific overexpression of lipoprotein lipase causes tissue-specific insulin resistance. Proc Natl Acad Sci U S A (2001) 5.48
CCR3 and CCR5 are co-receptors for HIV-1 infection of microglia. Nature (1997) 5.45
Disruption of the p70(s6k)/p85(s6k) gene reveals a small mouse phenotype and a new functional S6 kinase. EMBO J (1998) 5.34
Tumor induction of VEGF promoter activity in stromal cells. Cell (1998) 5.20
DNA excision in liver by an albumin-Cre transgene occurs progressively with age. Genesis (2000) 5.09
A candidate prostate cancer susceptibility gene at chromosome 17p. Nat Genet (2001) 5.06
Time-dependent vascular regression and permeability changes in established human tumor xenografts induced by an anti-vascular endothelial growth factor/vascular permeability factor antibody. Proc Natl Acad Sci U S A (1996) 5.04
Cross-bridge model of muscle contraction. Quantitative analysis. Biophys J (1980) 4.91
Use of arsenic trioxide (As2O3) in the treatment of acute promyelocytic leukemia (APL): II. Clinical efficacy and pharmacokinetics in relapsed patients. Blood (1997) 4.78
Prevention of fat-induced insulin resistance by salicylate. J Clin Invest (2001) 4.74
Gene expression profiling of alveolar rhabdomyosarcoma with cDNA microarrays. Cancer Res (1998) 4.68
Anti-inflammatory cyclopentenone prostaglandins are direct inhibitors of IkappaB kinase. Nature (2000) 4.66
Human prostate cancer and benign prostatic hyperplasia: molecular dissection by gene expression profiling. Cancer Res (2001) 4.51
Expression profiling of medulloblastoma: PDGFRA and the RAS/MAPK pathway as therapeutic targets for metastatic disease. Nat Genet (2001) 4.48
BRCA1 is secreted and exhibits properties of a granin. Nat Genet (1996) 4.26
Meta-analysis of the relationship between Helicobacter pylori seropositivity and gastric cancer. Gastroenterology (1998) 4.13
Identification of a peptide recognized by five melanoma-specific human cytotoxic T cell lines. Science (1994) 3.96
Mechanism of insulin resistance in A-ZIP/F-1 fatless mice. J Biol Chem (2000) 3.90
Comparative genomic hybridization analysis of 38 breast cancer cell lines: a basis for interpreting complementary DNA microarray data. Cancer Res (2000) 3.83
A comprehensive panel of near-full-length clones and reference sequences for non-subtype B isolates of human immunodeficiency virus type 1. J Virol (1998) 3.65
Interference of GTP hydrolysis in the mechanism of microtubule assembly: an experimental study. Proc Natl Acad Sci U S A (1984) 3.63
Risk factors for myocardial infarction and death in newly detected NIDDM: the Diabetes Intervention Study, 11-year follow-up. Diabetologia (1996) 3.62
Association of BRCA1 with the hRad50-hMre11-p95 complex and the DNA damage response. Science (1999) 3.47
Three distinct signalling responses by murine fibroblasts to genotoxic stress. Nature (1996) 3.37
Retinoblastoma protein positively regulates terminal adipocyte differentiation through direct interaction with C/EBPs. Genes Dev (1996) 3.32
Cooperative effects in models of steady-state transport across membranes. 3. Simulation of potassium ion transport in nerve. Proc Natl Acad Sci U S A (1970) 3.30
Mechanism of the cardiotoxic actions of terfenadine. JAMA (1993) 3.27
Targeted disruption of fibroblast growth factor (FGF) receptor 2 suggests a role for FGF signaling in pregastrulation mammalian development. Proc Natl Acad Sci U S A (1998) 3.27
Direct phosphorylation of IkappaB by IKKalpha and IKKbeta: discrimination between free and NF-kappaB-bound substrate. Science (1998) 3.26
Bound simian virus 40 translocates to caveolin-enriched membrane domains, and its entry is inhibited by drugs that selectively disrupt caveolae. Mol Biol Cell (1996) 3.23
beta-cell-specific deletion of the Igf1 receptor leads to hyperinsulinemia and glucose intolerance but does not alter beta-cell mass. Nat Genet (2002) 3.12
Assessment of gastric emptying using a low fat meal: establishment of international control values. Am J Gastroenterol (2000) 3.08
Scanning two-photon fluctuation correlation spectroscopy: particle counting measurements for detection of molecular aggregation. Biophys J (1996) 3.04
Plasma fibronectin supports neuronal survival and reduces brain injury following transient focal cerebral ischemia but is not essential for skin-wound healing and hemostasis. Nat Med (2001) 3.01
BRG1, a component of the SWI-SNF complex, is mutated in multiple human tumor cell lines. Cancer Res (2000) 3.01
An SNP map of human chromosome 22. Nature (2000) 2.99
Evidence that mycobacterial PE_PGRS proteins are cell surface constituents that influence interactions with other cells. Infect Immun (2001) 2.98
IL-6-deficient mice are resistant to experimental autoimmune encephalomyelitis: roles of IL-6 in the activation and differentiation of autoreactive T cells. J Immunol (1998) 2.97
TMPRSS2-ERG fusion, a common genomic alteration in prostate cancer activates C-MYC and abrogates prostate epithelial differentiation. Oncogene (2008) 2.94
Endothelial cell death, angiogenesis, and microvascular function after castration in an androgen-dependent tumor: role of vascular endothelial growth factor. Proc Natl Acad Sci U S A (1998) 2.92
Comparison of the ABI 7700 system (TaqMan) and competitive PCR for quantification of IS6110 DNA in sputum during treatment of tuberculosis. J Clin Microbiol (1998) 2.91
Rhythmic expression of timeless: a basis for promoting circadian cycles in period gene autoregulation. Science (1995) 2.87
Phase changes at the end of a microtubule with a GTP cap. Proc Natl Acad Sci U S A (1984) 2.87
The BRC repeats in BRCA2 are critical for RAD51 binding and resistance to methyl methanesulfonate treatment. Proc Natl Acad Sci U S A (1998) 2.85
Structural and magnetic phase diagram of CeFeAsO(1- x)F(x) and its relation to high-temperature superconductivity. Nat Mater (2008) 2.83
Pattern of non-steroidal anti-inflammatory drug use in Australia 1990-1994. A report from the Drug Utilization Sub-Committee of the Pharmaceutical Benefits Advisory Committee. Med J Aust (1996) 2.78
Predictors of aspiration pneumonia: how important is dysphagia? Dysphagia (1998) 2.76
Shigella-induced apoptosis is dependent on caspase-1 which binds to IpaB. J Biol Chem (1998) 2.75
JNK2 and IKKbeta are required for activating the innate response to viral infection. Immunity (1999) 2.74
Pharmacological characterization of the cloned kappa-, delta-, and mu-opioid receptors. Mol Pharmacol (1994) 2.70
Cooperative effects in models of steady-state transport across membranes. I. Proc Natl Acad Sci U S A (1970) 2.68
Imprinted X inactivation maintained by a mouse Polycomb group gene. Nat Genet (2001) 2.63
Impaired insulin secretion and beta-cell loss in tissue-specific knockout mice with mitochondrial diabetes. Nat Genet (2000) 2.62
Novel fluorescent protein from Discosoma coral and its mutants possesses a unique far-red fluorescence. FEBS Lett (2000) 2.61
Utility of adiponectin as a biomarker predictive of glycemic efficacy is demonstrated by collaborative pooling of data from clinical trials conducted by multiple sponsors. Clin Pharmacol Ther (2009) 2.60
L1 mono- and polyclonal antibodies modify cell migration in early postnatal mouse cerebellum. Nature (1983) 2.59
Evidence of bacterial metabolic activity in culture-negative otitis media with effusion. JAMA (1998) 2.58
Human H-Y: a male-specific histocompatibility antigen derived from the SMCY protein. Science (1995) 2.55
Resolving heterogeneity on the single molecular level with the photon-counting histogram. Biophys J (2000) 2.55
Termination of Ca2+ release by a local inactivation of ryanodine receptors in cardiac myocytes. Proc Natl Acad Sci U S A (1998) 2.49
A SNP resource for human chromosome 22: extracting dense clusters of SNPs from the genomic sequence. Genome Res (2001) 2.49
Quantitative subcellular imaging of glucose metabolism within intact pancreatic islets. J Biol Chem (1996) 2.45
NAK is an IkappaB kinase-activating kinase. Nature (2000) 2.44
Phosphoenolpyruvate carboxykinase is necessary for the integration of hepatic energy metabolism. Mol Cell Biol (2000) 2.42
Analysis of missense variation in human BRCA1 in the context of interspecific sequence variation. J Med Genet (2004) 2.40
Sequence-specific RNA binding by an SR protein requires RS domain phosphorylation: creation of an SRp40-specific splicing enhancer. Proc Natl Acad Sci U S A (1997) 2.34
Drosophila CBP is a co-activator of cubitus interruptus in hedgehog signalling. Nature (1997) 2.33
Superoxide dismutase enhances tolerance of freezing stress in transgenic alfalfa (Medicago sativa L.). Plant Physiol (1993) 2.32