Water stress changes the relationship between photosynthesis and stomatal conductance.

Understanding the relationship between stomatal conductance (g) and photosynthesis (A) under water stress conditions can improve the accuracy of land surface models for estimating the gas exchange of crop canopies with the atmosphere. However, little is known about the effect of water stress on this relationship in crops. A glasshouse experiment was, therefore, conducted to investigate changes in the linear relationship between g and A owing to water stress in rice and the association with soil moisture content.

Phytocyanin-encoding genes confer enhanced ozone tolerance in Arabidopsis thaliana.

Ozone is a phytotoxic air pollutant that has various damaging effects on plants, including chlorosis and growth inhibition. Although various physiological and genetic studies have elucidated some of the mechanisms underlying plant ozone sensitivity and lesion development, our understanding of plant response to this gas remains incomplete. Here, we show evidence for the involvement of certain apoplastic proteins called phytocyanins, such as AtUC5, that protect against ozone damage.

Prohydrojasmon Promotes the Accumulation of Phenolic Compounds in Red Leaf Lettuce.

Prohydrojasmon (PDJ) is a synthetic jasmonate derivative that is primarily used as a growth regulator, but its mechanism of action is unclear. In this study, we elucidated the effects of PDJ on phytochemical production in red leaf lettuce. The PDJ treatments promoted the accumulation of phenolic compounds in aerial plant parts.

Reconstruction method and optimum range of camera-shooting angle for 3D plant modeling using a multi-camera photography system.

Background: Measurement of plant structure is useful in monitoring plant conditions and understanding the responses of plants to environmental changes. 3D imaging technologies, especially the passive-SfM (Structure from Motion) algorithm combined with a multi-camera photography (MCP) system has been studied to measure plant structure due to its low-cost, close-range, and rapid image capturing ability. However, reconstruction of 3D plant models with complex structure is a time-consuming process and some systems have failed to reconstruct 3D models properly.

Genetic diversity and population structure of feral rapeseed (Brassica napus L.) in Japan.

Rapeseed (Brassica napus L.) is one of the most economically important oilseed crops worldwide. In Japan, it has been cultivated for more than a century and has formed many feral populations.

Ozone-Sensitive Arabidopsis Mutants with Deficiencies in Photorespiratory Enzymes.

An ozone-sensitive mutant was isolated from T-DNA-tagged lines of Arabidopsis thaliana. The T-DNA was inserted at a locus on chromosome 3, where two genes encoding glycolate oxidases, GOX1 and GOX2, peroxisomal enzymes involved in photorespiration, reside contiguously. The amounts of the mutant's foliar transcripts for these genes were reduced, and glycolate oxidase activity was approximately 60% of that of the wild-type plants.

Mitogen-activated protein kinase 4-like carrying an MEY motif instead of a TXY motif is involved in ozone tolerance and regulation of stomatal closure in tobacco.

The mitogen-activated protein kinases (MAPKs/MPKs) are important factors in the regulation of signal transduction in response to biotic and abiotic stresses. Previously, we characterized a MAPK from tobacco, Nicotiana tabacum MPK4 (NtMPK4). Here, we found a highly homologous gene, NtMPK4-like (NtMPK4L), in tobacco as well as other species in Solanaceae and Gramineae.

Fixed-route monitoring and a comparative study of the occurrence of herbicide-resistant oilseed rape (Brassica napus L.) along a Japanese roadside.

Previously, we conducted a roadside survey to reveal the occurrence of genetically modified (GM) oilseed rape along a Japanese roadside (Route 51). In this study, we performed successive and thorough fixed-route monitoring in 5 sections along another road (Route 23). Oilseed rape plants were detected on both sides of the road in each section between autumn 2009 and winter 2013, which included 3 flowering seasons.

Arabidopsis BNT1, an atypical TIR-NBS-LRR gene, acting as a regulator of the hormonal response to stress.

During their life cycle, plants have to cope with fluctuating environmental conditions. The perception of the stressful environmental conditions induces a specific stress hormone signature specifying a proper response with an efficient fitness. By reverse genetics, we isolated and characterized a novel mutation in Arabidopsis, associated with environmental stress responses, that affects the At5g11250/BURNOUT1 (BNT1) gene which encode a Toll/Interleukin1 receptor-nucleotide binding site leucine-rich repeat (TIR-NBS-LRR) protein.

High-throughput capture of nucleotide sequence polymorphisms in three Brassica species (Brassicaceae) using DNA microarrays.

Premise Of The Study: To capture molecular markers that are applicable to environmental risk assessment of genetically modified oilseed rape, and to streamline their development, we screened variations in nucleotide sequences of three Brassica species by DNA microarray analysis.

Methods And Results: Using the Affymetrix GeneChip Arabidopsis ATH1 Genome Array, we monitored gene expression at 22810 loci among the Brassica species and picked out 192 putative polymorphic loci. We sequenced 25 of these and successfully aligned them among all three species.

Seeds of a possible natural hybrid between herbicide-resistant Brassica napus and Brassica rapa detected on a riverbank in Japan.

Transgenic herbicide-resistant varieties of Brassica napus, or oilseed rape, from which canola oil is obtained, are imported into Japan, where this plant is not commercially cultivated to a large extent. This study aimed to examine the distribution of herbicide-resistant B. napus and transgene flow to escaped populations of its closely related species, B.

Rapeseed species and environmental concerns related to loss of seeds of genetically modified oilseed rape in Japan.

Feral rapeseed in Japan consists of Brassica rapa, B. juncea and B. napus, mostly produced by escape from crops.

Has Arabidopsis SWEETIE protein a role in sugar flux and utilization?

In plants, sugars affect growth and development and play an important role in the intricate machinery of signal transduction. Understanding the mechanisms behind the flux of sugar in the plant is of central interest. We recently characterized an Arabidopsis mutant: sweetie, which is defective in the control of growth and development, sterile, shows premature senescence and affects sugar metabolism.

Ethylene and salicylic acid control glutathione biosynthesis in ozone-exposed Arabidopsis thaliana.

Ozone produces reactive oxygen species and induces the synthesis of phytohormones, including ethylene and salicylic acid. These phytohormones act as signal molecules that enhance cell death in response to ozone exposure. However, some studies have shown that ethylene and salicylic acid can instead decrease the magnitude of ozone-induced cell death.

Monitoring the occurrence of genetically modified oilseed rape growing along a Japanese roadside: 3-year observations.

Monitoring for escape of genetically modified (GM) oilseed rape (Brassica napus) during transport can be performed by means of roadside evaluations in areas where cultivation of this GM crop is not conducted, such as in Japan. We performed a survey of oilseed rape plants growing along a 20-km section of Japan's Route 51, one of the main land transportation routes in central Japan for imports of GM oilseed rape from the Port of Kashima into Keiyo District. Oilseed rape plants were found each year, but the number of plants varied substantially during the three years of our study: 2162 plants in 2005, 4066 in 2006, and only 278 in 2007.

An unidentified ultraviolet-B-specific photoreceptor mediates transcriptional activation of the cyclobutane pyrimidine dimer photolyase gene in plants.

Cyclobutane pyrimidine dimers (CPDs) constitute a majority of DNA lesions caused by ultraviolet-B (UVB). CPD photolyase, which rapidly repairs CPDs, is essential for plant survival under sunlight containing UVB. Our earlier results that the transcription of the cucumber CPD photolyase gene (CsPHR) was activated by light have prompted us to propose that this light-driven transcriptional activation would allow plants to meet the need of the photolyase activity upon challenges of UVB from sunlight.

The Arabidopsis sweetie mutant is affected in carbohydrate metabolism and defective in the control of growth, development and senescence.

Sugars modulate many vital metabolic and developmental processes in plants, from seed germination to flowering, senescence and protection against diverse abiotic and biotic stresses. However, the exact mechanisms involved in morphogenesis, developmental signalling and stress tolerance remain largely unknown. Here we report the characterization of a novel Arabidopsis thaliana mutant, sweetie, with drastically altered morphogenesis, and a strongly modified carbohydrate metabolism leading to elevated levels of trehalose, trehalose-6-phosphate and starch.

Disruption of a gene encoding C4-dicarboxylate transporter-like protein increases ozone sensitivity through deregulation of the stomatal response in Arabidopsis thaliana.

To understand better the plant response to ozone, we isolated and characterized an ozone-sensitive (ozs1) mutant strain from a set of T-DNA-tagged Arabidopsis thaliana ecotype Columbia. The mutant plants show enhanced sensitivity to ozone, desiccation and sulfur dioxide, but have normal sensitivity to hydrogen peroxide, low temperature and high light levels. The T-DNA was inserted at a single locus which is linked to ozone sensitivity.

SAZ, a new SUPERMAN-like protein, negatively regulates a subset of ABA-responsive genes in Arabidopsis.

Arabidopsis SUPERMAN (SUP) and members of its family are plant-unique C(2)H(2)-type zinc finger genes that have been implicated in plant growth and development. In this paper, we report that a new SUP-family gene, designated as S A- and A BA-downregulated z inc finger gene (SAZ), is involved in the negative regulation of ABA-mediated signaling. SAZ-GUS fusion proteins were predominantly localized in the nuclei when they were transiently expressed in onion epidermal cells.

Glycosylation of bisphenol A by freshwater microalgae.

The endocrine disruptor bisphenol A (BPA, 4,4'-isopropylidenediphenol) is used to manufacture polycarbonate plastic and epoxy resin linings of food and beverage cans, and the residues from these products are then sometimes discharged into rivers and lakes in waste leachates. However, the fate of BPA in the environment has not yet been thoroughly elucidated. Considering the effect of BPA on aquatic organisms, it is important that we estimate the concentration of BPA and its metabolites in the aquatic environment, but there are few data on the metabolites of BPA.

The isochorismate pathway is negatively regulated by salicylic acid signaling in O3-exposed Arabidopsis.

Ozone (O3), a major photochemical oxidant, causes leaf injury in plants. Plants synthesize salicylic acid (SA), which is reported to greatly affect O3 sensitivity. However, the mechanism of SA biosynthesis under O3 exposure remains unclear.

Induction of isoforms of tetrapyrrole biosynthetic enzymes, AtHEMA2 and AtFC1, under stress conditions and their physiological functions in Arabidopsis.

In the tetrapyrrole biosynthetic pathway, isoforms of glutamyl-tRNA reductase (HEMA2) and ferrochelatase1 (FC1) are mainly expressed in nonphotosynthetic tissues. Here, using promoter-beta-glucuronidase constructs, we showed that the expressions of Arabidopsis (Arabidopsis thaliana) HEMA2 (AtHEMA2) and FC1 (AtFC1) were induced in photosynthetic tissues by oxidative stresses such as wounding. Transcript levels and beta-glucronidase activity were rapidly induced within 30 min, specifically in the wound area in a jasmonate-independent manner.

Detection of feral transgenic oilseed rape with multiple-herbicide resistance in Japan.

Repeated monitoring for escaped transgenic crop plants is sometimes necessary, especially in cases when the crop has not been approved for release into the environment. Transgenic oilseed rape (Brassica napus) was detected along roadsides in central Japan in a previous study. The goal of the current study was to monitor the distribution of transgenic oilseed rape and occurrence of hybridization of transgenic B.

O2- activates leaf injury, ethylene and salicylic acid synthesis, and the expression of O3-induced genes in O3-exposed tobacco.

O3 is the major component of photochemical oxidants and gives rise to visible injuries on plant leaves. In O3-exposed plants, O2- is produced before the formation of the injury, but the role that O2- plays in plant response to 03 exposure is still unknown. To clarify its role, we observed the behavior of plants during O3 exposure after pretreatment with tiron, which is an O2- scavenger.

Development of visible markers for transgenic plants and their availability for environmental risk assessment.

Monitoring of transgenic plants in the field is important, but risk assessment has entailed laborious use of invisible marker genes. Here, we assessed three easily visible marker transgenes--green fluorescent protein (GFP), R, and Nicotiana tabacum homeobox (NTH) 15 genes--for their potential use as marker genes for monitoring genetically modified plants. Transgenic Arabidopsis thaliana plants for each of these genes were visibly distinguished from wild-type plants.