Deep-sequencing of Solanum commersonii small RNA libraries reveals riboregulators involved in cold stress response

Among wild species used in potato breeding, Solanum commersonii displays the highest tolerance to low temperatures under both acclimated (ACC) and non-acclimated (NACC) conditions. It is also the first wild potato relative with a known whole genome sequence. Recent studies have shown that abiotic stresses induce changes in the expression of many small non-coding RNA (sncRNA). We determined the small non-coding RNA (sncRNAome) of two clones of S. commersonii contrasting in their cold response phenotypes via smRNAseq. Differential analysis provided evidence that expression of several miRNAs changed in response to cold stress conditions. Conserved miR408a and miR408b changed their expression under NACC conditions, whereas miR156 and miR169 were differentially expressed only under ACC conditions. We also report changes in tasiRNA and secondary siRNA expression under both stress conditions. Our results reveal possible roles of sncRNA in the regulatory networks associated with tolerance to low temperatures and provide useful information for a more strategic use of genomic resources in potato breeding.

Phenotypic and molecular characterization of plants regenerated from non-cryopreserved and cryopreserved wild Solanum lycopersicum mill. Seeds

BACKGROUND

Before cryopreservation is routinely used, its effect on the trueness-to-type of the regenerated plant material needs to be evaluated.

OBJECTIVE

In this work, we studied the effect of seed cryopreservation on the phenotypic and molecular characteristics of wild Solanum lycopersicum Mill. plants.

METHODS

Thirty-five morphological traits of plants regenerated from cryopreserved seeds were compared to those measured on plants regenerated from non-cryopreserved seeds.

RESULT

No statistically significant differences were observed between cryopreserved and non-cryopreserved samples, either in the first or in the second generation post-liquid nitrogen exposure. However, at the molecular level, the genetic analyses performed on the second generation plants germinated from control and cryopreserved seeds using 14 nuclear Simple Sequences Repeats (SSR) markers uncovered some changes in microsatellite length between control and cryopreserved samples. These results confirm at the botanical phenotype level the effectiveness of seed cryostorage for conservation and regeneration of true-to-type S. lycopersicum plants.

CONCLUSION

Further experiments are required to clarify potential phenotypic effects of the changes observed in the DNA.