Crop growth and yield depend on canopy light interception (LI). To identify a low-cost and relatively efficient index for measuring LI, several color attributes of red-green-blue (RGB), hue-saturation-intensity (HSI), hue-saturation-value (HSV) color models and the component values of color attributes in the RGB color model were investigated using digital images at six cotton plant population densities in 2012–2014. The results showed that the LI values followed downward quadratic curves after planting. The red (R), green (G) and blue (B) values varied greatly over the years, in accordance with Cai’s research demonstrating that the RGB model is affected by outside light. Quadratic curves were fit to these color attributes at six plant population densities. Additionally, linear regressions of LI on every color attribute revealed that the hue (H) values in HSI and HSV were significantly linearly correlated with LI with a determination coefficient (R²)≥0.89 and a root mean square error (RMSE)=0.05. Thus, the H values in the HSI and HSV models could be used to measure LI, and this hypothesis was validated. The H values are new indexes for quantitatively estimating the LI of heterogeneous crop canopies, which will provide a theoretical basis for optimizing the crop canopy structure. However, further research should be conducted in other crops and under other growing and environmental conditions to verify this finding.

Streptomyces rubrogriseus HDZ-9-47, isolated from eggs of Meloidogyne spp., was evaluated as a potential biocontrol agent of Meloidogyne incognita under in vitro and protective field.  Microscopic observations showed that HDZ-9-47 parasitized eggs of M. incognita within 7 days.  In vitro, the culture filtrate of HDZ-9-47 caused 97.0% mortality of second-stage juveniles (J2s) of M. incognita and inhibited more than 50% egg hatching.  In the field, compared with the control, the root-knot index and J2s density in the treatment of drench the broth contained 10¹² HDZ-9-47 spores were respectively reduced by 51.1 and 80.7% at 90 days post transplantation, which were better than that in other application doses and methods.  In addition, reduction rates of root-knot index and J2s density of the treatment of combined application of HDZ-9-47 with biofumigation was 87.1 and 91.0%, respectively, better than either of HDZ-9-47 or biofumigation used alone or fosthiazate treatment.  And tomato yield also increased by 16.1%.  Together, our results suggest that HDZ-9-47 could be an effective biocontrol agent of M. incognita, and that application of HDZ-9-47 combined with cabbage residue biofumigation was a promising and sustainable option for M. incognita control.

Seeds play a central role in the life cycle of plants. Seed hardness in pomegranates is of economic relevance, yet scarcely studied and poorly understood in China. In this study, we compared the proteomic differences between Zhongnonghong (soft-seeded) and Sanbai (hard-seeded) pomegranates. A total of 892 protein spots from both varieties were detected on two-dimensional electrophoresis gels (2-DE); 76 spots showed greater than a 1.5-fold or less than a 0.66-fold difference (P<0.05) in Zhongnonghong compared to Sanbai, of which 24 exhibited greater than a 2-fold change. Compared with Sanbai, Zhongnonghong possessed 14 up-regulated, and 10 down-regulated proteins. We identified and annotated 5 of these by using MALDI-TOF-TOF MS: pyruvate dehydrogenase (PDH) E1-β family protein (spot 4 609); alanine aminotransferase 2-like (ALT2L); mitochondrial glycine decarboxylase complex P-protein (spot 5 803); phosphofructokinase B (PfkB)-type family of carbohydrate kinase (spot 8 411); and putative dnaK-type molecular chaperone heat shock cognate protein 70 (Hsc70) (spot 9 006). Of these, 3 proteins (spots 4 609, 5 608, 5 803) were hypothesized to play a role in the formation of seed hardness. The other two proteins (spots 8 411, 9 006) were theorized to play a role in protecting the seeds from adverse stress during periods of fruit maturation. This study sets the foundation for further research on molecular mechanisms related to pomegranate seed hardness.

Copper nanoparticle is a new material widely used in biological medicine, animal husbandry and industrial areas, but its potential toxicity to human health and environment remains unclear. In order to study the hepatotoxic mechanisms of nanoparticles copper, two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI/TOF MS) of proteomics technology were used to isolate and identify the differentially expressed proteins from liver, which associated with hepatotoxicity induced by copper nanoparticle in rats. In this study, we have screened 15 kinds of proteins related with hepatotoxicity, of which spot8212 was identified as Malate dehydrogenase (Mdh1). The mRNA expression trend of Mdh1 was consistent with the result of 2-DE by RT-PCR validation. Bioinformatics analysis showed that Mdh1 was stable and no signal peptides, subcellular location was in endoplasmic reticulum; it contained many functional sites such as malate dehydrogenase activity signal sites 155LTRLDHNRAKSQI167; α helixes and random coils were the two main elements. Homologous analysis demonstrated high homologous of Mdh1 in rats with mouse and human, and the phylogenetic tree of Mdh1 was constructed. The result indicated that copper nanoparticle could regulate up the Mdh1 protein expression so as to compensate the energy deficit. Energy metabolic disturbance may be a pathway for copper nanoparticle particles to exert the hepatotoxic effects in rats.