Transcriptional analysis of adult cutting and juvenile seedling olive roots

Abstract

In woody plants, the juvenile-to-adult transition occurs when the apical and lateral branches reach a sufficient distance from the roots. In olive trees, there is a minimum distance required between the root and the meristem for flowering to occur. However, the way in which the roots may influence the apical meristem to develop juvenile or adult branches is still unknown; despite that, it is of great relevance for breeders. In addition, as in most fruit trees, olive cultivars are propagated by cuttings, while genetic breeding is performed by seedlings. The roots of both types of plants, cuttings, and seedlings, originate from different tissues, giving rise to differences between the two types of roots. For these reasons, we have studied the gene expression differences between the two types of roots in olive plants by microarray hybridization and found 253 genes differentially expressed, 126 over-expressed in roots of adult cuttings, and 127 in roots of juvenile seedlings. The genes over-expressed in cutting roots showed a similar distribution of genes in metabolic and biosynthetic processes, but juvenile seedling roots showed 20 % of over-expressed genes associated with lipid biosynthesis and metabolism processes, while these processes were absent in the over-expressed genes of adult cutting roots and in general, seedling over-expressed root genes are more diverse and evenly distributed than in cutting roots. In addition, eight root-specific genes have been identified.

Tolerance of olive (Olea europaea) cv Frantoio to Verticillium dahliae relies on both basal and pathogen‐induced differential transcriptomic responses

“…Overexpression of the DIRIGENT1 gene in cotton, leading to an enhanced lignification process and hampered invasion by V. dahliae , has been reported (Shi et al ., ). Finally, a pathogenesis‐related protein of the Bet v I family, probably encoding a major latex protein involved in pathogen defence responses, is a specific root gene in olive (Jiménez‐Ruiz et al ., ). Remarkably, this gene was found to be repressed in ‘Picual’, but not in ‘Frantoio’, upon infection by V. dahliae .…”

Gene Expression Pattern in Olive Tree Organs (Olea europaea L.)

“…In the present work, the specific transcriptomic profile in this crop's main organs is reported using "Picual" as the model cultivar for its relevance for both the scientific community and breeders who seek higher productivity and olive oil quality. Together with genomic data, previous transcriptomic studies of olive tree in response to stresses [9][10][11][12], during plant development [13][14][15][16] or across different plant organs, represent valuable information in the search for the key genes involved in different relevant traits for agronomical purposes.…”