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While many data are available on genes encoding proteins for degradation of hydrocarbons in bacteria, the impact of alkane on transporter protein expression is unclear. Pseudomonas aeruginosa SJTD-1 is a strain that can consume medium- and long-chain n-alkanes. In order to study the proteins involved in n-octadecane uptake, we use iTRAQ and label free comparative proteomics analysis to identify the proteins of alkane uptake in response to n-octadecane (C18) comparing with n-hexadecane (C16) in P. aeruginosa SJTD-1. A total of 1102 and 1249 proteins were identified by iTRAQ-based and label free quantitative methodologies, respectively. By application of 1.5 (iTRAQ) or 2-fold (label free) for upregulated and 0.65 (iTRAQ) or 0.5-fold (label free) for downregulated cutoff values, 91 and 99 proteins were found to be differentially expressed comparing SJTD-1 cultivated on C18 with C16 respectively. There are six proteins with the common differential expression by iTRAQ and label free-based methods. Results of bioinformational analysis suggested the involvement of bacterial chemotaxis in responds to C18. Additionally, quantitative reverse transcriptase PCR (qRT-PCR) results confirmed C18-induced change in levels of FleQ, FliC, NirS, FadL and FadD proteins and the role of the proteins in n-octadecane uptake was further discussed in P. aeruginosa. In conclusion, results of the present study provided information about possible target-related proteins of bacterial chemotaxis, swimming performance, alkane transport to stimulus of n-ctadecane rather than n-hexadecane in P. aeruginosa SJTD-1. [ABSTRACT FROM AUTHOR]

Warm temperature during post-heading is generally hypothesized to be the critical factor limiting grain yield of early-rice in South China. However, there is no direct evidence to confirm this hypothesis in the field. This study was conducted to determine the temperature-related yield constraints of early-rice in South China. Field experiments were carried out in Huaiji (a location in South China) and Changsha (a location in the Yangtze River basin) in 2011–2013. In each year, two rice cultivars were grown in early-rice growing season in Huaiji and in single-rice growing season in Changsha. Huaiji had higher average daily maximum temperature during post-heading than Changsha. The higher temperature during post-heading induced early plant senescence (slower crop growth rate and shorter grain filling duration), but grain weight did not reduce because it was compensated for by increased translocation of pre-heading biomass. The higher temperature during post-heading also did not cause a reduction in grain filling percentage. Huaiji had lower temperature during pre-heading than Changsha, which to some extent resulted in slower crop growth rate and consequently lower biomass production and smaller sink size in Huaiji than in Changsha. As a result, grain yield was about 30% lower in Huaiji than in Changsha. Our results indicate that grain yield of early-rice in South China is limited not by warm temperature during post-heading but partially by cool temperature during pre-heading, and suggest that enhancing sink size and meanwhile maintaining good translocation of pre-heading biomass may be an effective way to achieve high yield for early-rice in South China. [ABSTRACT FROM AUTHOR]