Volatiles Versus Vegetation Plants act as both global sources and sinks of highly reactive volatile organic compounds (VOCs). Models typically treat the uptake and degradation of these compounds as if they are mostly unreactive, like other more commonly studied biogenic gases such as ozone. A study by Karl et al. (p. 816 , published online 21 October) suggests that VOCs may be more reactive than expected. By monitoring six field sites representing a range of deciduous ecosystems, several oxidized VOCs were found to have high deposition fluxes. Fumigation experiments in the laboratory confirmed that leaves are capable of oxidizing these compounds, and do so through an enzymatic detoxification or stress-response mechanism. Budgets for VOC flux in the atmosphere suggests that, on a global scale, plants may take up significant levels of VOCs in polluted regions, especially in the tropics.

Terpene is a natural compound with various medical properties and found in both plants and animals (Gershenzon 2007). Among natural products that mediate antagonistic and beneficial interactions within the organism, terpene play a variety of roles (Gershenzon 2007). Terpene protects many living organisms like microorganisms, animals and plants from abiotic and biotic stresses (Gershenzon 2007). Terpene can ward off pathogens, predators, and competitors. Living organisms use terpene for multiple reasons like medicinal purposes and communications about food, mates, or enemies (Gershenzon 2007). It is impressive how different organisms use terpene for common purposes even though terpene contain many forms and varieties (Gershenzon 2007). So far only a small percentage of terpene is investigated (Franklin et al. 2001). Cannabis is one of the most common sources for the medicinal terpene (Franklin et al. 2001). This plant contains many medicinal properties like anticancer, antimicrobial, antifungal, antiviral, antihyperglycemic, analgesic, anti-inflammatory, and antiparasitic (Franklin et al. 2001). Terpene is also used to enhance skin penetration, prevent inflammatory diseases (Franklin et al. 2001). Nowadays modern medication use large scales of terpene for various treatment drugs (Franklin et al. 2001). There are commonly used plants like tea (Melaleuca alternifolia), thyme, Cannabis, Salvia lavandulifolia (Spanish sage), citrus fruits (lemon, orange, mandarin) etc. that provide wide range of medicinal values (Perry et al. 2000). Tea tree oil has increased in popularity in recent years when it comes to alternative medicine (Perry et al. 2000). Tea tree oil is a volatile essential oil and is famous for its antimicrobial properties, and acts as the active ingredient that is used to treat cutaneous infections (Carson et al. 2006) Apart from the flavor that gives to food, essential oil contain antimicrobial properties (Bound et al. 2015). Thyme is one of plants that synthesize terpene alcohols and phenols which contain powerful antibacterial and antifungal properties (Bound et al. 2015). Terpene synthesized from cannabis also long served as medicines (Perry et al. 2000). They also contain psychoactive properties and used against many infectious diseases (Perry et al. 2000). Salvia lavandulifolia is famous for anti-dementia (current memory-enhancing) drugs by enhancing Table 15.1 Different types of terpenes and their properties Classification Carbon atoms Species produced from Medicinal uses References Monoterpenes C 10 Quercus ilex Fragrances, repellent Loreto et al. (2002) Sesquiterpenes C 15 Helianthus annuus Treat malaria, treat bacterial infections, and migraines Chadwick et al. (2013) Diterpenes C 20 Euphorbia, salvia miltiorrhiza Anti-inflammatory, cardiovascular diseases Vasas and Hohmann (2014), Zhang et al. (2012) Triterpenes C 30 Centella asiatica Wound healing, increases circulation James and Dubery (2009) D. Cox-Georgian et al.

Real‐time PCR (quantitative PCR or qPCR) has become the preferred method for validating results obtained from assays which measure gene expression profiles. The process uses reverse transcription polymerase chain reaction (RT‐PCR), coupled with fluorescent chemistry, to measure variations in transcriptome levels between samples. The four most commonly used fluorescent chemistries are SYBR® Green dyes and TaqMan®, Molecular Beacon or Scorpion probes. SYBR® Green is very simple to use and cost efficient. As SYBR® Green dye binds to any double‐stranded DNA product, its success depends greatly on proper primer design. Many types of online primer design software are available, which can be used free of charge to design desirable SYBR® Green‐based qPCR primers. This laboratory exercise is intended for those who have a fundamental background in PCR. It addresses the basic fluorescent chemistries of real‐time PCR, the basic rules and pitfalls of primer design, and provides a step‐by‐step protocol for designing SYBR® Green‐based primers with free, online software. Biochemistry and Molecular Biology Education Vol. 39, No. 2, pp. 145–154, 2011

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Drought and heat are among the major abiotic stresses that affect soybean crops worldwide. During the current investigation, the effect of drought, heat, and drought plus heat stresses was compared in the leaves of two soybean varieties, Surge and Davison, combining 2D-DIGE proteomic data with physiology and biochemical analyses. We demonstrated how 25 differentially expressed photosynthesis-related proteins affect RuBisCO regulation, electron transport, Calvin cycle, and carbon fixation during drought and heat stress. We also observed higher abundance of heat stress-induced EF-Tu protein in Surge. It is possible that EF-Tu might have activated heat tolerance mechanisms in the soybean. Higher level expressions of heat shock-related protein seem to be regulating the heat tolerance mechanisms. This study identifies the differential expression of various abiotic stress-responsive proteins that regulate various molecular processes and signaling cascades. One inevitable outcome from the biochemical and proteomics assays of this study is that increase of ROS levels during drought stress does not show significant changes at the phenotypic level in Davison and this seems to be due to a higher amount of carbonic anhydrase accumulation in the cell which aids the cell to become more resistant to cytotoxic concentrations of H2O2.

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Quantitative real-time polymerase chain reaction (qPCR) is a powerful tool for analysis and quantification of gene expression. It is advantageous compared to traditional gel-based method of PCR, as gene expression can be visualized "real-time" using a computer. In qPCR, a reporter dye system is used which intercalates with DNA's region of interest and detects DNA amplification. Some of the popular reporter systems used in qPCR are the following: Molecular Beacon(®), SYBR Green(®), and Taqman(®). However, success of qPCR depends on the optimal primers used. Some of the considerations for primer design are the following: GC content, primer self-dimer, or secondary structure formation. Freely available software could be used for ideal qPCR primer design. Here we have shown how to use some freely available web-based software programs (such as Primerquest(®), Unafold(®), and Beacon designer(®)) to design qPCR primers.

Transcription factors (TFs) are proteinaceous complex, which bind to the promoter regions in the DNA and affect transcription initiation. Plant TFs control gene expressions and genes control many physiological processes, which in turn trigger cascades of biochemical reactions in plant cells. The databases available for plant TFs are somewhat abundant but all convey different information and in different formats. Some of the publicly available plant TF databases may be narrow, while others are broad in scopes. For example, some of the best TF databases are ones that are very specific with just one plant species, but there are also other databases that contain a total of up to 20 different plant species. In this review plant TF databases ranging from a single species to many will be assessed and described. The comparative analyses of all the databases and their advantages and disadvantages are also discussed.