Untethered small actuators have various applications in multiple fields. However, existing small-scale actuators are very limited in their intractability with their surroundings, respond to only a single type of stimulus and are unable to achieve programmable structural changes under different stimuli. Here, we present a multiresponsive patternable actuator that can respond to humidity, temperature and light, via programmable structural changes. This capability is uniquely achieved by a fast and facile method that was used to fabricate a smart actuator with precise patterning on a graphene oxide film by hydrogel microstamping. The programmable actuator can mimic the claw of a hawk to grab a block, crawl like an inchworm, and twine around and grab the rachis of a flower based on their geometry. Similar to the large- and small-scale robots that are used to study locomotion mechanics, these small-scale actuators can be employed to study movement and biological and living organisms.

Soil rhizospheric metaproteomics is a powerful scientific tool to uncover the interactions between plants and microorganisms in the soil ecosystem. The present study established an extraction method suitable for different soils that could increase the extracted protein content. Close to 1000 separate spots with high reproducibility could be identified in the stained 2-DE gels. Among the spots, 189 spots representing 122 proteins on a 2-DE gel of rice soil samples were successfully identified by MALDI-TOF/TOF-MS. These proteins mainly originated from rice and microorganisms. They were involved in protein, energy, nucleotide, and secondary metabolisms, as well as signal transduction and resistance. Three characteristics of the crop rhizospheric metaproteomics seemed apparent: (1) approximately one-third of the protein spots could not be identified by MALDI-TOF/TOF/MS, (2) the conservative proteins from plants formed a feature distribution of crop rhizospheric metaproteome, and (3) there were very complex interactions between plants and microorganisms existing in a crop rhizospheric soil. Further functional analysis on the identified proteins unveiled various metabolic pathways and signal transductions involved in the soil biotic community. This study provides a paradigm for metaproteomic research on soil biology.

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Screening crop accessions for allelopathic activity is of paramount importance for crop allelopathy research. Previous bioassays often did not use a mixed culture of donor and target plants, did not use soil and were not conducted under natural conditions. In this study, we designed an inhibitory-circle method in which a rice accession (donor plant) and Echinochloa crus-galli (target plant) were cultured together in paddy soil under natural conditions. First, we determined that the highest allelopathic activity of allelopathic rice accession PI312777 was at the 5-leaf stage, and the suitable distance of rice seedlings and E. crus-galli was 12 cm apart. This method was then validated by a field test. A further 40 rice accessions were evaluated for allelopathic activity to E. crus-galli using this method. Two rice accessions, PI312777 and Taichung Native 1, had highly allelopathic activity to E. crus-galli (inhibitory rate > 50%), while another accession, Lemont, had non-allelopathic activity. These experimental results were in accordance with previous studies using direct field experiments. The inhibitory-circle method integrated three necessary conditions, that is donor and target plants grown together, with soil as the medium and under natural conditions for reliable results. The 'inhibitory-circle method', which combined donor and target plants, soil medium and field conditions, can give reliable results in one step, compared with laboratory screening methods. Also, the 'inhibitory-circle method' gave results in 30-35 days, thereby substantially reducing the requirements for time, labour and cost.

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Using rice allelopathy to control weeds in paddy fields is a sustainable bio-engineering technique of the 21 st century. The main objective of the study was to analyze the relationship between rice allelopathic potential and its grain yield. To that end, 5 different allelopathic rice accessions (allelopathic rice of "PI-1", "Taichung Native 1", "Azucena", "IAC47"; non-allelopathic rice "Lemont") were analyzed for companion weed biomass and rice grain yield under field conditions in 2008~2010. The results indicated that weed biomass was the highest under non-allelopathic rice "Lemont" and the lowest under allelopathic rice "PI-1". Furthermore, allelopathic rice "PI-1" had the highest and non-allelopathic "Lemont" had the lowest inhibitory effect on weed. Hence allelopathic rice "PI-1" had the highest grain yield and the reverse was true in "Lemont" under non weeding treatment. Allelopathic rice "PI-1" also had the highest while "IAC47" had the lowest grain yield under weeding treatment. The correlation analysis on weed biomass, rice allelopathic potential and rice yield indicated that grain yields of different allelopathic rice accessions were significantly negatively correlated with weed biomass while significantly positively correlated with allelopathic potential. The results suggested that allelopathic rice "PI-1" had the highest inhibition effect on paddy field weeds, the reverse was true in the case of non-allelopathic "Lemont" in the comparison of 5 different allelopathic rice accessions. Without weeding treatment, "PI-1" grain yield also exceeded those of the other rice accessions. Thus rice accession "PI-1" was the strongest allelopathic accession with the highest grain yield among the 5 rice accessions, the reverse was true in the case of "Lemont".

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