The Arabidopsis tetratricopeptide thioredoxin-like gene family is required for osmotic stress tolerance and male sporogenesis.
TETRATRICOPEPTIDE THIOREDOXIN-LIKE (TTL) proteins are characterized by the presence of six tetratricopeptide repeats in conserved positions and a carboxyl-terminal region known as the thioredoxin-like domain with homology to thioredoxins. In Arabidopsis (Arabidopsis thaliana), the TTL gene family is composed by four members, and the founder member, TTL1, is required for osmotic stress tolerance. Analysis of sequenced genomes indicates that TTL genes are specific to land plants. In this study, we report the expression profiles of Arabidopsis TTL genes using data mining and promoter-reporter β-glucuronidase fusions. Our results show that TTL1, TTL3, and TTL4 display ubiquitous expression in normal growing conditions but differential expression patterns in response to osmotic and NaCl stresses. TTL2 shows a very different expression pattern, being specific to pollen grains. Consistent with the expression data, ttl1, ttl3, and ttl4 mutants show reduced root growth under osmotic stress, and the analysis of double and triple mutants indicates that TTL1, TTL3, and TTL4 have partially overlapping yet specific functions in abiotic stress tolerance while TTL2 is involved in male gametophytic transmission.
Instituto de Hortofruticultura Subtropical y Mediterránea, Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Departamento de Biología Molecular y Bioquímica, Universidad de Málaga, Campus de Teatinos, E-29071 Malaga, Spain.
Naoufal
N
Lakhssassi
Verónica G
VG
Doblas
Abel
A
Rosado
Alicia Esteban
AE
del Valle
David
D
Posé
Antonio J
AJ
Jimenez
Araceli G
AG
Castillo
Victoriano
V
Valpuesta
Omar
O
Borsani
Miguel A
MA
Botella
D000222:Adaptation, Physiological; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D029681:Arabidopsis Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D019295:Computational Biology; D057225:Data Mining; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D017930:Genes, Reporter; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D005810:Multigene Family; D009154:Mutation; D010802:Phylogeny; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D011058:Pollen / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology; D013312:Stress, Physiological
D029681:Arabidopsis Proteins; D011993:Recombinant Fusion Proteins; C516469:TTL1 protein, Arabidopsis; D012965:Sodium Chloride; D005966:Glucuronidase