Phenotyping plays an important role in crop science research; the accurate and rapid acquisition of phenotypic information of plants or cells in different environments is helpful for exploring the inheritance and expression patterns of the genome to determine the association of genomic and phenotypic information to increase the crop yield. Traditional methods for acquiring crop traits, such as plant height, leaf color, leaf area index (LAI), chlorophyll content, biomass and yield, rely on manual sampling, which is time-consuming and laborious. Unmanned aerial vehicle remote sensing platforms (UAV-RSPs) equipped with different sensors have recently become an important approach for fast and non-destructive high throughput phenotyping and have the advantage of flexible and convenient operation, on-demand access to data and high spatial resolution. UAV-RSPs are a powerful tool for studying phenomics and genomics. As the methods and applications for field phenotyping using UAVs to users who willing to derive phenotypic parameters from large fields and tests with the minimum effort on field work and getting highly reliable results are necessary, the current status and perspectives on the topic of UAV-RSPs for field-based phenotyping were reviewed based on the literature survey of crop phenotyping using UAV-RSPs in the Web of Science™ Core Collection database and cases study by NERCITA. The reference for the selection of UAV platforms and remote sensing sensors, the commonly adopted methods and typical applications for analyzing phenotypic traits by UAV-RSPs, and the challenge for crop phenotyping by UAV-RSPs were considered. The review can provide theoretical and technical support to promote the applications of UAV-RSPs for crop phenotyping.

The conjugation reaction between whey protein isolate (WPI) and dextran in aqueous solutions via the initial stage of the Maillard reaction was studied. The covalent attachment of dextran to WPI was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with both protein and carbohydrate staining. The formation of WPI-dextran conjugates was monitored by a maximum absorbance peak at approximately 304 nm using difference UV spectroscopy. The impact of various processing conditions on the formation of WPI-dextran conjugates was investigated. The conjugation reaction was promoted by raising the temperature from 40 to 60 degrees C, the WPI concentration from 2.5 to 10%, and the dextran concentration from 10 to 30% and lowering the pH from 8.5 to 6.5. The optimal conjugation conditions chosen from the experiments were 10% WPI-30% dextran and pH 6.5 at 60 degrees C for 24 h. WPI-dextran conjugates were stable under the conditions studied.

The WRKY-type transcription factors are involved in plant development and stress responses, but how the regulation of stress tolerance is related to plant development is largely unknown. GsWRKY20 was initially identified as a stress response gene using large-scale Glycine soja microarrays. Quantitative reverse transcription-PCR (qRT-PCR) showed that the expression of this gene was induced by abscisic acid (ABA), salt, cold, and drought. Overexpression of GsWRKY20 in Arabidopsis resulted in a decreased sensitivity to ABA during seed germination and early seedling growth. However, compared with the wild type, GsWRKY20 overexpression lines were more sensitive to ABA in stomatal closure, and exhibited a greater tolerance to drought stress, a decreased water loss rate, and a decreased stomatal density. Moreover, microarray and qRT-PCR assays showed that GsWRKY20 mediated ABA signalling by promoting the expression of negative regulators of ABA signalling, such as AtWRKY40, ABI1, and ABI2, while repressing the expression of the positive regulators of ABA, for example ABI5, ABI4, and ABF4. Interestingly, GsWRKY20 also positively regulates the expression of a group of wax biosynthetic genes. Further, evidence is provided to support that GsWRKY20 overexpression lines have more epicuticular wax crystals and a much thicker cuticle, which contribute to less chlorophyll leaching compared with the wild type. Taken together, the findings reveal an important role for GsWRKY20 in enhancing drought tolerance and regulating ABA signalling.

The physicochemical and emulsifying properties of protein and polysaccharide conjugates prepared under mild conditions were investigated. The covalently linked conjugates of whey protein isolate (WPI) and dextran (DX, 440 kDa) were produced by incubating aqueous solutions containing 10% WPI and 30% DX at pH 6.5 and 60 degrees C for 48 h. After purification by anion-exchange chromatography and affinity chromatography, the conjugate had a weight-average molecular weight (M(w)) of 531 kDa and a radius of gyration (R(g)) of 30 nm as determined by size exclusion chromatography-multiangle laser light scattering (SEC-MALLS); the molar binding ratio of WPI to DX was calculated to be approximately 1:1. The purified conjugate had significantly improved heat stability when subjected to 80 degrees C for 30 min and remained soluble over a range of pH from 3.2 to 7.5 and ionic strengths from 0.05 to 0.2 M in contrast to native WPI. The emulsifying ability and emulsion stability made with WPI-DX conjugate were also improved compared to WPI and gum arabic (an emulsifier containing naturally derived glycoproteins).

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