Proteomic profiles of young and mature cocoa leaves subjected to mechanical stress caused by wind

Integrated physiological, proteome and gene expression analyses provide new insights into nitrogen remobilization in citrus trees

Nitrogen (N) remobilization is an important physiological process that supports the growth and development of trees. However, in evergreen broad-leaved tree species, such as citrus, the mechanisms of N remobilization are not completely understood. Therefore, we quantified the potential of N remobilization from senescing leaves of spring shoots to mature leaves of autumn shoots of citrus trees under different soil N availabilities and further explored the underlying N metabolism characteristics by physiological, proteome and gene expression analyses. Citrus exposed to low N had an approximately 38% N remobilization efficiency (NRE), whereas citrus exposed to high N had an NRE efficiency of only 4.8%. Integrated physiological, proteomic and gene expression analyses showed that photosynthesis, N and carbohydrate metabolism interact with N remobilization. The improvement of N metabolism and photosynthesis, the accumulation of proline and arginine, and delayed degradation of storage protein in senescing leaves are the result of sufficient N supply and low N remobilization. Proteome further showed that energy generation proteins and glutamate synthase were hub proteins affecting N remobilization. In addition, N requirement of mature leaves is likely met by soil supply at high N nutrition, thereby resulting in low N remobilization. These results provide insight into N remobilization mechanisms of citrus that are of significance for N fertilizer management in orchards.

Tear Film Proteome of Healthy Domestic Cats

The aim of this study was to investigate the proteins found in tear film of healthy domestic cats. Schirmer tear test strips were used to collect tear samples of twelve healthy cats, which were mixed, centrifuged, and placed in a single 1.5 mL microtube that was frozen at −20°C, until analysis by two-dimensional polyacrylamide gel and mass spectrometry associated with high-performance liquid chromatography. The resulting spectra were analyzed and compared with the Swiss-Prot search tool. Forty peptides were detected in the analyzed protein fragments of 90 spots, with 16 proteins identified. Of these, the authors confirmed what has been already found in other studies: lactotransferrin, serum albumin, allergenic lipocalins, and neutrophil gelatinase-associated lipocalin. Others were considered novel in tear film samples of all species: cyclin-dependent protein kinase, serine/arginine repetitive matrix protein, apelin receptor, secretory protein related to C1q/TNF, Wee1, α-1,4 glucan phosphorylase, and WD repeat domain 1. The network was divided into 11 clusters, and a biological function was assigned. Most of the proteins have functions in the defense and maintenance of feline ocular surface homeostasis. Serum albumin is a bottleneck protein, with a high betweenness value. This paper is a pioneer in reporting, in-depth, the tear film proteome of domestic cats.