The epidermis plays crucial roles in the development of various organs and in water retention in both animals and plants. In Arabidopsis thaliana, the subtilase ABNORMAL LEAF SHAPE 1 (ALE1) and the Arabidopsis homolog of the Crinkly4 (ACR4) receptorlike protein kinase (RLK) have been implicated in the intercellular communication that is required for surface functions of the epidermis. We have identified a novel mutant gene in Arabidopsis, ale2, which is associated with various epidermal defects, including disorganization of epidermis-related tissues, defects in the leaf cuticle and the fusion of organs. ALE2 encodes a previously uncharacterized RLK with a cluster of basic amino acid residues followed by a cysteine-containing sequence in the putative extracellular domain. Our genetic investigations suggest that ALE2 and ACR4 function in the same process, whereas ALE1 has a different mode of action, and that these three genes play partially overlapping roles in positively regulating protodermspecific gene expression and for the formation of leafy organs. We propose that at least two modes of intercellular communication facilitate the specification of epidermis, thereby promoting shoot organogenesis in Arabidopsis.

Background: Some natural substances may affect the expression of microRNAs (miRNAs) in humans. However, it is unclear whether this effect can be induced by the ingestion of whole foods containing these natural substances. Objective: We investigated whether ingestion of the whole food FFC ® Pairogen affects the expression of miRNAs in humans. Design: This was a pilot study and part of a randomized controlled trial. Four subjects ingested the test material daily for 8 weeks (three times 180 ml bottles a day, morning, noon and evening; a total of 540 ml per day). The study did not include control subjects. Results: Several miRNAs showed differential expression. The expression of two miRNAs, hsa-let-7c and hsa-miR-92a-2-5p, changed in three of the four subjects, who had lower concentration of serum total antioxidant status. The expression of hsa-let-7c increased and that of hsa-miR-92a-2-5p decreased. Conclusions: The expression of hsa-let-7c and hsa-miR-92a-2-5p has been linked with lung cancer manifestation. The increased expression of hsa-let-7c and the decreased expression of hsa-miR-92a-2-5p suggest possible oncogene suppressive functions of these miRNAs. The ingestion of FFC ® Pairogen may have a positive effect on cancer prevention.