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Auxin controls numerous processes in plant development and auxin/indoleacetic acid (Aux/IAA), an auxin response factor (ARF), and a lateral organ boundaries domain (LBD) were considered as early auxin response transcription factors (TFs). Till now, no Aux/IAA, ARF, and LBD TFs were identified in ramie (Boehmeria nivea L. Gaud). In this study, we used Arabidopsis and mulberry sequences as query to search against the ramie transcriptome database and the searched sequences were analyzed for a full-length coding sequence. In total, we obtained 16 BnAux/IAA, 14 BnARF, and 16 BnLBD TFs on which evolutionary analysis and expression profiling were conducted. Analysis of sequence conservation revealed close evolution relationships between ramie and mulberry. Expression analysis shows these genes were actively expressed in major ramie tissues, and several were auxin responsive. The expressions of these genes were also investigated under drought and a high temperature, main abiotic stresses during ramie life cycle. We found that most genes of the three families were stress-responsive and showed distinct expression patterns under the drought and high temperature stresses.

Although significant progresses have been made in sensor technology, it is still a challenging task to develop ultrasensitive sensors to monitor very weak and low frequency vibration signal for early warning of natural disasters and efficient structural health monitoring of infrastructures. It has been reported from previous experiments that some fishes have acute sensitivities to extremely low frequency linear acceleration due to the otolith organs of the inner ear. In this paper, based on the experimental results and qualitative mechanism of the infrasound sensitivity of some fishes conducted by other researchers, a bioinspired gating spring model with negative stiffness is established to simulate the mechanical-electricity transduction of the hair cell in fish ear. Then, numerical analyses of the mechanical model subject to static and dynamic loading are conducted, respectively. It is shown that the gating model has adaptive amplification capability to weak and low frequency excitation compared with the corresponding linear model. This mechanism can be used for the design of bioinspired ultrasensitive sensors for monitoring weak and low frequency vibration signal.