Homeologous genes involved in mannitol synthesis reveal unequal contributions in response to abiotic stress in Coffea arabica

• Published in: Molecular genetics and genomics : MGG Vol. 289; no. 5; pp. 951 - 963
• Main Authors: de Carvalho, Kenia, Petkowicz, Carmen L. O, Nagashima, Getulio T, Bespalhok Filho, João C, Vieira, Luiz G. E, Pereira, Luiz F. P, Domingues, Douglas S
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.10.2014; Springer Berlin Heidelberg; Springer Nature B.V
• Subjects: Abiotic stress; Animal Genetics and Genomics; Biochemistry; Biomedical and Life Sciences; Biosynthesis; Biosynthetic Pathways - genetics; Coffea; Coffea - genetics; Coffea - metabolism; Coffea arabica; Coffea canephora; Coffee; crop production; Dehydration - metabolism; Dehydrogenases; drought; environmental factors; Enzymes; fructose; Fructose - metabolism; gene expression regulation; Gene Expression Regulation, Plant; Genes; Genes, Plant; Genomics; heat stress; Heat-Shock Response; High temperature; Human Genetics; leaves; Life Sciences; mannitol; Mannitol - metabolism; Metabolites; Microbial Genetics and Genomics; Original Paper; Phylogeny; Plant Genetics and Genomics; Plant Proteins - genetics; Plant Proteins - metabolism; polyploidy; Salinity; salt stress; Salt-Tolerance; Signal transduction; stress tolerance; temperature; transcription (genetics); Transcription, Genetic; Brazil; Salt stress; Homeologous genes; Water deficit; Mannitol; Mannose-6-phosphate reductase; Phosphomannose-isomerase; Mannitol dehydrogenase; High temperature
• ISSN: 1617-4615; 1617-4623
• DOI: 10.1007/s00438-014-0864-y

Polyploid plants can exhibit transcriptional modulation in homeologous genes in response to abiotic stresses. Coffea arabica, an allotetraploid, accounts for 75 % of the world’s coffee production. Extreme temperatures, salinity and drought limit crop productivity, which includes coffee plants. Mannitol is known to be involved in abiotic stress tolerance in higher plants. This study aimed to investigate the transcriptional responses of genes involved in mannitol biosynthesis and catabolism in C. arabica leaves under water deficit, salt stress and high temperature. Mannitol concentration was significantly increased in leaves of plants under drought and salinity, but reduced by heat stress. Fructose content followed the level of mannitol only in heat-stressed plants, suggesting the partitioning of the former into other metabolites during drought and salt stress conditions. Transcripts of the key enzymes involved in mannitol biosynthesis, CaM6PR, CaPMI and CaMTD, were modulated in distinct ways depending on the abiotic stress. Our data suggest that changes in mannitol accumulation during drought and salt stress in leaves of C. arabica are due, at least in part, to the increased expression of the key genes involved in mannitol biosynthesis. In addition, the homeologs of the Coffea canephora subgenome did not present the same pattern of overall transcriptional response, indicating differential regulation of these genes by the same stimulus. In this way, this study adds new information on the differential expression of C. arabica homeologous genes under adverse environmental conditions showing that abiotic stresses can influence the homeologous gene regulation pattern, in this case, mainly on those involved in mannitol pathway.