Gene expression changes in response to drought stress in Ilex paraguariensis leaves

ACEVEDO, RAÚL M.; RUIZ, OSCAR A.; SANSBERRO, PEDRO A.

PLANT OMICS

SOUTHERN CROSS PUBL

Año: 2016 vol. 9 p. 334 - 343

1836-0661

Under the prevailing agro-climatic conditions in NE Argentina, high temperatures and lack of rains in spring and summer, cause drought stress to Ilex paraguariensis (yerba mate) in crop fields during most of its period of potential growth. Analysis of gene expression changes using mRNA Differential Display and validated by Real-Time PCR was used to study the response to drought stress. We found 52 differentially expressed transcripts (DETs), by analysing of banding patterns on Differential Display polyacrylamide gels, 38 DETs were induced, and 14 DETs were repressed in response to drought. Sequence comparison with data available revealed that 19 % of the fragments showed no homologies, whereas 40.5 % of the total number of fragments had strong similarities with database entries of known functions. The other DETs belonged to unclassified proteins or genes with unknown functions. The identified genes were assigned to specific functional categories based on a careful analysis of the scientific literature. Interestingly, 12 % of the DNA sequences were related to signal transduction, and 2 % of the sequences were identified as transcription factors. Approximately, 12 % of the annotated sequences were involved in stress tolerance and metal homeostasis, while 7 % of the DETs were associated with photosynthesis. Other groups, representing 12 %, included those involved in secondary metabolism, lignin biosynthesis, cell walls, RNA stabilization/chaperone activity. When integrated with physiological data, our results suggest that the transcriptional activity of some of the studied genes could be related to the degree of drought tolerance/susceptibility of I. paraguariensis.