Microscopic Investigation on Morphologies of Bilayer Gel Structure in the Mixed Polyoxyethylene-Type Nonionic Surfactant Systems

We investigated morphologies of lamellar domains below the Krafft temperature in the mixed polyoxyethylene-type nonionic surfactant, a C₁₆E₆/C₁₆E₇/water system, by using optical microscopy, confocal microscopy, small/wide-angle X-ray scattering, and small-angle neutron scattering. We have found that the morphology discontinuously changes from network structures of lamellar domains to spherical vesicles with increasing mole fraction of C₁₆E₇, via the coexistence region of vesicles and network structures of lamellar domains

Involvement of STH7 in light-adapted development in <i>Arabidopsis thaliana</i> promoted by both strigolactone and karrikin

<p>Strigolactones (SLs) and karrikins (KARs) regulate photomorphogenesis. GR24, a synthetic SL and KAR₁, a KAR, inhibit the hypocotyl elongation of <i>Arabidopsis thaliana</i> in a weak light. GR24 and KAR₁ up-regulate the expression of <i>STH7</i>, encoding a transcription factor belonging to the double B-box zinc finger subfamily. In this study, we used <i>STH7</i>-overexpressing (<i>STH7ox</i>) lines and functionally defective <i>STH7</i> (<i>STH7</i>-<i>SRDX</i>) mutants to investigate roles of SLs and KARs in photomorphogenesis of <i>Arabidopsis</i>. Hypocotyl elongation of <i>STH7</i>-<i>SRDX</i> mutants was less sensitive to both GR24 and KAR₁ treatment than that of wild-type <i>Arabidopsis</i> under weak light conditions. Furthermore, the chlorophyll and anthocyanin content was increased in <i>STH7ox</i> lines when de-etiolated with light and GR24-treated plants had enhanced anthocyanin production. GR24 and KAR₁ treatment significantly increased the expression level of photosynthesis-related genes <i>LHCB1</i> and <i>rbcS</i>. The results strongly suggest that SL and KAR induce photomorphogenesis of <i>Arabidopsis</i> in an STH7-dependent manner.</p> <p>Strigolactone response is mediated by D14 and KAI2 while karrikin response is mediated by only KAI2.</p