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The cuticle is a hydrophobic structure that seals plant aerial surfaces from the surrounding environment. To better understand how cuticular wax composition changes over development, we conducted an untargeted screen of leaf surface lipids from black cottonwood (Populus trichocarpa). We observed major shifts to the lipid profile across development, from a phenolic and terpene-dominated profile in young leaves to an aliphatic wax-dominated profile in mature leaves. Contrary to the general pattern, levels of aliphatic cis-9-alkenes decreased in older leaves following their accumulation. A thorough examination revealed that the decrease in cis-9-alkenes was accompanied by a concomitant increase in aldehydes, one of them being the volatile compound nonanal. By applying exogenous alkenes to P. trichocarpa leaves, we show that unsaturated waxes in the cuticle undergo spontaneous oxidative cleavage to generate aldehydes and that this process occurs similarly in other alkene-accumulating systems such as balsam poplar (Populus balsamifera) leaves and corn (Zea mays) silk. Moreover, we show that the production of cuticular wax-derived compounds can be extended to other wax components. In bread wheat (Triticum aestivum), 9-hydroxy-14,16-hentriacontanedione likely decomposes to generate 2-heptadecanone and 7-octyloxepan-2-one (a caprolactone). These findings highlight an unusual route to the production of plant volatiles that are structurally encoded within cuticular wax precursors. These processes could play a role in modulating ecological interactions and open the possibility for engineering bioactive volatile compounds into plant waxes.
Asunto(s)
Aldehídos , Populus , Ceras/química , Hojas de la Planta/química , Triticum/química , Alquenos , Zea mays , Epidermis de la PlantaRESUMEN
BACKGROUND: Nanoparticles derived from plant viruses possess fascinating structures, versa-tile functions and safe properties, rendering them valuable for a variety of applications. Papaya mosaic Virus-Like Particles (VLPs) are nanoparticles that contain a repetitive number of virus capsid proteins (PMV-CP) and are considered to be promising platforms for vaccine design. Previous studies have re-ported the antigenicity of PMV nanoparticles in mammalian systems. MATERIALS AND METHODS: As experiments that concern vaccine development require careful design and can be time consuming, computational experiments are of particular importance. Therefore, prior to ex-pressing PMV-CP in E. coli and producing nanoparticles, we performed an in silico analysis of the virus particles using software programs based on a series of sophisticated algorithms and modeling networks as useful tools for vaccine design. A computational study of PMV-CP in the context of the immune sys-tem reaction allowed us to clarify particle structure and other unknown features prior to their introduc-tion in vitro. RESULTS: The results illustrated that the produced nanoparticles can trigger an immune response in the absence of fusion with any foreign antigen. CONCLUSION: Based on the in silico analyses, the empty capsid protein was determined to be recognised by different B and T cells, as well as cells which carry MHC epitopes.
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BACKGROUND: High affinity potassium transporters (HKTs) are located in the plasma membrane of the vessels and have significant influence on salt tolerance in some plants. They exclude Na(+) from the parenchyma cells to reduce Na(+) concentration. Despite many studies, the underlying regulatory mechanisms and the exact functions of HKTs within different genomic backgrounds are relatively unknown. In this study, various bioinformatics techniques, including promoter analysis, identification of HKT-surrounding genes, and construction of gene networks, were applied to investigate the HKT regulatory mechanism. RESULTS: Promoter analysis showed that rice HKTs carry ABA response elements. Additionally, jasmonic acid response elements were detected on promoter region of TmHKT1;5. In silico synteny highlighted several unknown and new loci near rice, Arabidopsis thaliana and Physcomitrella patent HKTs, which may play a significant role in salt stress tolerance in concert with HKTs. Gene network prediction unravelled that crosstalk between jasmonate and ethylene reduces AtHKT1;1 expression. Furthermore, antiporter and transferase proteins were found in AtHKT1;1 gene network. Interestingly, regulatory elements on the promoter region of HKT in wild genotype (TmHKT1;5) were more frequent and variable than the ones in cultivated wheat (TaHKT1;5) which provides the possibility of rapid response and better understanding of environmental conditions for wild genotype. CONCLUSION: Detecting ABA and jasmonic acid response elements on promoter regions of HKTs provide valuable clues on underlying regulatory mechanisms of HKTs. In silico synteny and pathway discovery indicated several candidates which act in concert with HKTs in stress condition. We highlighted different arrangement of regulatory elements on promoter region of wild wheat (TmHKT1;5) compared to bread wheat (TaHKT1;5) in this study.