Transforming the Snapdragon Aurone Biosynthetic Genes into Petunia Alters Coloration Patterns in Transgenic Flowers

Aurones belong to a small class of flavonoids that provide yellow color in some floricultural plants including snapdragon. To explore novel flower coloration, two full-length cDNAs encoding chalcone 4'-O-glucosyltransferase (designated as SRY4'CGT) and aureusidin synthase (designated as SRYAS1) in the aurone biosynthetic pathway were cloned from yellow flowers of snapdragon (Antirrhinum majus cv. Ribbon Yellow). Binary vectors were constructed and transformed separately into Petunia hybrida harboring blue flowers. Only a few flowers in 4 out of 9 transgenic SRY4'CGT plants showed variegated blue-white sectors;as time passed, amounts of variegated flowers and proportion of white sectors in the background blue color of the new-born flowers gradually increased, until finally, the petal color was completely white in all late-born flowers. In contrast, a few flowers in 3 out of 13 transgenic SRYAS1 plants showed variegated blue-white sectors;but, the amounts of variegated flowers did not increase over the whole flowering stage, and no complete white flowers were observed. RNA samples isolated from blue and white sectors of T1 transgenic SRY4'CGT plants were analyzed by reverse transcription-PCR, transgenic SRY4'CGT transcripts were detected in both sectors;however, transcripts of an upstream gene, chalcone synthase (CHS), were abundantly detected in the blue sectors but largely reduced in the white sectors, suggesting that the expression of CHS gene was suppressed in white sectors of transgenic plants. Furthermore, HPLC coupled with mass spectrometry demonstrated cyandin, malvidin and their derivatives were absent in white sectors, causing the white phenotype. Our findings may be attractive to molecular breeders.

Mechanically driven assembly of biomimetic 2D-material microtextures with bioinspired multifunctionality

Nature provides a wealth of bio-inspiration for advanced material research.Assembling various nanomaterials into biomimetic microtextures with bioinspired functionalities has spurred increasing research interests and facilitated technological advances in various applications.In recent years,two-dimensional materials(2DMs)have emerged as important building block units in the biomimicry field due to their distinct chemical,physical,electrical,electrochemical,and catalytic properties.In this review article,various mechanically driven assembly approaches are summarized to fabricate various genealogies of biomimetic 2DM microtextures with bio-inspired multifunctionality.First,sequential deformation strategies are discussed to programmably construct higher dimensional 2DM microtextures,ranging from wrinkles/crumples(one-time deformation)to multiscale hierarchies(multiple deformations).Next,the current progress using higher dimensional 2DM microtextures to imitate different biological structures and/or induce bio-inspired multifunctionality is systematically summarized.Four showcases of bio-inspiration and biomimicry using different 2DM nanosheets are highlighted:(1)wrinkle patterns of an earthworm that spur the design of strain sensors with programmable working ranges and sensitivities,(2)wrinkle appearance of a Shar-Pei dog that motivates the fabrication of stretchable energy storage devices,(3)hierarchical scale textures of a desert lizard that inspire cation-induced gelation platforms for 2DM aerogels,and(4)wrinkle skin of an elephant that influences the development of 2DM protective skin for soft robots.Finally,challenges and future opportunities of adopting 2DM nanosheets to assemble biomimetic microstructures with synergistic functionalities are discussed.

A Review of Printable Flexible and Stretchable Tactile Sensors

Flexible and stretchable tactile sensors that are printable,nonplanar,and dynamically morphing are emerging to enable proprioceptive interactions with the unstructured surrounding environment.Owing to its varied range of applications in the field of wearable electronics,soft robotics,human-machine interaction,and biomedical devices,it is required of these sensors to be flexible and stretchable conforming to the arbitrary surfaces of their stiff counterparts.The challenges in maintaining the fundamental features of these sensors,such as flexibility,sensitivity,repeatability,linearity,and durability,are tackled by the progress in the fabrication techniques and customization of the material properties.This review is aimed at summarizing the recent progress of rapid prototyping of sensors,printable material preparation,required printing properties,flexible and stretchable mechanisms,and promising applications and highlights challenges and opportunities in this research paradigm.