Search

The NAC proteins are the largest transcription factors in plants. The functions of NACs are various and we focus on their roles in response to abiotic stress here. In our study, a typical NAC gene (SlNAM1) is isolated from tomato and its product is located in the nucleus. It also has a transcriptional activity region situated in C-terminal. The expression levels of SlNAM1 in tomato were induced by 4°C, PEG, NaCl, abscisic acid (ABA) and methyl jasmonate (MeJA) treatments. The function of SlNAM1 in response to chilling stress has been investigated. SlNAM1 overexpression in tobacco exhibited higher germination rates, minor wilting, and higher photosynthetic rates (Pn) under chilling stress. Meanwhile, overexpression of SlNAM1 improved the osmolytes contents and reduced the H2O2 and O2•- contents under low temperature, which contribute to alleviating the oxidative damage of cell membrane after chilling stress. Moreover, the transcripts of NtDREB1, NtP5CS, and NtERD10s were higher in transgenic tobacco, and those increased expressions may confer higher chilling tolerance of transgenic plants. These results indicated that overexpression of SlNAM1 could improve chilling stress tolerance of transgenic tobacco.

The NAC transcription factor (TF) is one of the largest families of TFs in plants and plays an important role in plant growth, development, and response to environmental stress. The structural and functional characteristics of NAC TFs have been uncovered in the past years, including sequence binding features of the DNA-binding domain located in the N-terminus and dynamic interplay between the domain located at the C-terminus and other proteins. Studies on NAC TF are increasing in number; these studies distinctly contribute to our understanding of the regulatory networks of NAC-mediated complex signaling and transcriptional reprogramming. Previous studies have indicated that NAC TFs are key regulators of the plant stress response. However, these studies have been for six years so far and mainly focused on drought and salt stress. There are relatively few reports about NAC TFs in plant cold signal pathway and no related reviews have been published. In this review article, we summarize the structural features of NAC TFs, the target genes, upstream regulators and interaction proteins of stress-responsive NAC TFs, and the roles NAC TFs play in plant cold stress signal pathway.

Heat stress poses a major threat to plant productivity and crop yields. The induction of heat shock proteins (HSPs) by heat shock factors is a principal defense response of plants exposed to heat stress. In this study, we identified and analyzed the heat stress-induced Whirly1 (SlWHY1) gene in tomato (Solanum lycopersicum). We generated various SlWHY1-overexpressing (OE) and SlWHY1-RNA interference (RNAi) lines to investigate the role of WHIRLY1 in thermotolerance. Compared with the wild type (WT), the OE lines showed less wilting, as reflected by their increased membrane stability and soluble sugar content and reduced reactive oxygen species (ROS) accumulation under heat stress. By contrast, RNAi lines with inhibited SlWHY1 expression showed the opposite phenotype and corresponding physiological indices under heat stress. The heat-induced gene SlHSP21.5A, encoding an endoplasmic reticulum-localized HSP, was upregulated in the OE lines and downregulated in the RNAi lines compared with the WT. RNAi-mediated inhibition of SlHSP21.5A expression also resulted in reduced membrane stability and soluble sugar content and increased ROS accumulation under heat stress compared with the WT. SlWHY1 binds to the elicitor response element-like element in the promoter of SlHSP21.5A to activate its transcription. These findings suggest that SlWHY1 promotes thermotolerance in tomato by regulating SlHSP21.5A expression.

DnaJ proteins, which are molecular chaperones that are widely present in plants, can respond to various environmental stresses. At present, the function of DnaJ proteins was studied in many plant species, but only a few studies were conducted in tomato. Here, we examined the functions of a novel tomato (Solanum lycopersicum) DnaJ protein (SlDnaJ20) in heat tolerance using sense and antisense transgenic tomatoes. Transient conversion assays of Arabidopsis protoplasts showed that SlDnaJ20 was targeted to chloroplasts. Expression analysis showed that SlDnaJ20 expression was induced by chilling, NaCl, polyethylene glycol, and H2O2, especially via heat stress. Under heat stress, sense plants showed higher fresh weights, chlorophyll content, fluorescence (Fv/Fm), and D1 protein levels, and a lower accumulation of reactive oxygen species (ROS) than antisense plants. These results suggest that SlDnaJ20 overexpression can reduce the photoinhibition of photosystem II (PSII) by relieving ROS accumulation. Moreover, higher expression levels of HsfA1 and HsfB1 were observed under heat stress in sense plants, indicating that SlDnaJ20 overexpression contributes to HSF expression. The yeast two-hybrid system proved that SlDnaJ20 can interact with the chloroplast heat-shock protein 70. Our results indicate that SlDnaJ20 overexpression enhances the thermotolerance of transgenic tomatoes, whereas suppression of SlDnaJ20 increases the heat sensitivity of transgenic tomatoes.

In plants, the chilling response involves decreased photosynthetic capacity and increased starch accumulation in chloroplasts. However, the mechanisms that modulate these processes remain unclear. We found that the SlWHY1 gene is significantly induced by chilling stress (4°C) in tomato. Three SlWHY1 overexpression (OE) lines grew better than the wild type (WT) under chilling stress; the OE plants retained intact photosynthetic grana lamellae and showed enhanced hydrolysis of starch. By contrast, RNAi lines that inhibited SlWHY1 were more affected than the corresponding WT cultivar. Their grana lamellae were damaged and starch content increased. The psbA gene encodes the key photosystem II (PSII) protein D1. We show that SlWHY1 binds to the upstream region (A/GTTACCCT/A) of SlpsbA and enhances the de novo synthesis of D1 in chloroplasts. Additionally, SlWHY1 regulates the expression of the starch-degrading enzyme α-amylase (SlAMY3-L) and the starch synthesis-related enzyme isoamylase gene (SlISA2) in the nucleus, thus modulating the starch content in chloroplasts. We demonstrate that SlWHY1 enhances the resistance of tomato to chilling stress by maintaining the function of PSII and degrading starch. Thus, overexpression of WHY1 may be an effective strategy for enhancing resistance to chilling stress of chilling-sensitive crops in agricultural production.

Background: Preclinical studies have demonstrated that β-adrenergic receptor antagonists could improve the prognosis of breast cancer. However, the conclusions of clinical and pharmacoepidemiological studies have been inconsistent. This review was conducted to re-assess the relationship between beta-adrenoceptor blockers and breast cancer prognosis. Materials and Methods: The literature was searched from PubMed, EMBASE and Web of Nature (Thompson Reuters) databases through using key terms, such as breast cancer and betaadrenoceptor blockers. Results: Ten publications met the inclusion criteria. Six suggested that receiving betaadrenoceptor blockers reduced the risk of breast cancer–specific mortality, and three of them had statistical significance (hazard ratio (HR)=0.42; 95% CI=0.18-0.97; p=0.042). Two studies reported that risk of recurrence and distant metastasis (DM) were both significantly reduced. One study demonstrated that the risk of relapsefree survival (RFS) was raised significantly with beta-blockers (BBS) (HR= 0.30; 95% CI=0.10-0.87; p=0.027). One reported longer disease-free interval (Log Rank (LR)=6.658; p=0.011) in BBS users, but there was no significant association between overall survival (OS) and BBS (HR= 0.35; 95% CI=0.12–1.0; p=0.05) in five studies. Conclusions: Through careful consideration, it is suggested that beta-adrenoceptor blockers use may be associated with improved prognosis in breast cancer patients. Nevertheless, larger size studies are needed to further explore the relationship between beta-blocker drug use and breast cancer prognosis.

Gamma-aminobutyric acid (GABA) is a non-protein amino acid that accumulates in a number of plant species under various environmental stresses. In this paper, the ability of applied GABA for the alleviation of NaCl stress was investigated in view of growth parameters, gas exchange, photosynthetic pigments, chlorophyll fluorescence, activities of antioxidant enzymes, malondialdehyde (MDA) content, and electrolyte conductivity (REC) in wheat seedlings. Germination rate and shoot dry mass decreased with an increasing NaCl concentration and this decrease was less pronounced when 0.5 mM GABA was applied. In the NaCl-treated seedlings, exogenous GABA partially enhanced photosynthetic capacity and antioxidant enzyme activities and decreased MDA content and REC. Therefore, GABA reduced the impact of salinity on the wheat seedlings.

In Drosophila melanogaster prothoracic gland (PG) cells, Torso mediates prothoracicotropic hormone (PTTH)-triggered mitogen activated protein kinase (MAPK) pathway (consisting of four core components Ras, Raf, MEK and ERK) to stimulate ecdysteroidogenesis. In this study, LdTorso, LdRas, LdRaf and LdERK were cloned in Leptinotarsa decemlineata. The four genes were highly or moderately expressed in the larval prothoracic glands. At the first- to third-instar stages, their expression levels were higher just before and right after the molt, and were lower in the mid instars. At the fourth-instar stage, their transcript levels were higher before prepupal stage. RNA interference-mediated knockdown of LdTorso delayed larval development, increased pupal weight, and impaired pupation and adult emergence. Moreover, knockdown of LdTorso decreased the mRNA levels of LdRas, LdRaf and LdERK, repressed the transcription of two ecdysteroidogenesis genes (LdPHM and LdDIB), lowered 20E titer, and downregulated the expression of several 20E-response genes (LdEcR, LdUSP, LdHR3 and LdFTZ-F1). Furthermore, silencing of LdTorso induced the expression of a JH biosynthesis gene LdJHAMT, increased JH titer, and activated the transcription of a JH early-inducible gene LdKr-h1. Thus, our results suggest that Torso transduces PTTH-triggered MAPK signal to regulate ecdysteroidogenesis in the PGs in a non-drosophiline insect.

A new high-gain cylindrical Dielectric res- onator antenna (DRA) with a large bandwidth is proposed. A cylindrical Dielectric resonator (DR), a double-annular patch and a metallic cylinder are used to obtain a large bandwidth and a high gain. The mode TM12 excited in the patch is used to enhance the gain of the DRA, and the cavity formed by the metallic cylinder provides a further higher gain and a larger bandwidth. The measured results demonstrate that the proposed DRA achieves a large band- width of 23% from 5.3 to 6.8GHz with VSWR less than two and a high gain around 11 dBi. In this paper, a new broadband, high-gain DRA design is proposed using a double-annular patch and a conducting cav- ity formed by a concentric metallic cylinder. Firstly, a single- annular patch is used to improve the gain of the DRA. After- ward, a double-annular patch is used to achieve a large gain bandwidth. Finally, a metallic cylinder is introduced to en- hance the resonating and obtain a higher gain. The antenna is manufactured and measured in the microwave anechoic cham- ber. The results of simulations and measurements are com- pared together, showing a good agreement. The results show that the antenna provides a further higher gain and a larger bandwidth using the proposed double-annular patch and a metallic cylinder.

BACKGROUND Juvenile hormone (JH) plays a critical role in the regulation of metamorphosis in Leptinotarsa decemlineata, a notorious defoliator of potato. JH acid methyltransferase (JHAMT) is involved in one of the final steps of JH biosynthesis. RESULTS A putative JHAMT cDNA (LdJHAMT) was cloned. Two double-stranded RNAs (dsRNAs) (dsJHAMT1 and dsJHAMT2) against LdJHAMT were constructed and bacterially expressed. Experiments were conducted to investigate the effectiveness of RNAi in both second- and fourth-instar larvae. Dietary introduction of dsJHAMT1 and dsJHAMT2 successfully knocked down the target gene, lowered JH titre in the haemolymph and reduced the transcript of Kruppel homologue 1 gene. Ingestion of dsJHAMT caused larval death and weight loss, shortened larval developmental period and impaired pupation. Moreover, the dsJHAMT-fed pupae exhibited lower adult emergence rates. The resulting adults weighed an average of 50 mg less than the control group, and the females did not deposit eggs. Application of pyriproxyfen to the dsJHAMT-fed insects rescued all the negative effects. CONCLUSIONS LdJHAMT expresses functional JHAMT enzyme. The RNAi targeting LdJHAMT could be used for control of L. decemlineata. © 2015 Society of Chemical Industry

Study Objective To evaluate the safety and efficacy of a new crosslinked hyaluronan (NCH) gel in reducing postoperative adhesions. Design Randomized controlled trial (Canadian Task Force classification I). Settings Seven departments of obstetrics and gynecology in China. Patients A total of 216 women scheduled for gynecologic laparoscopic surgery for primary removal of adhesions, myomas, ovarian cysts, or endometriotic cysts. Interventions Patients were randomized to receive either NCH gel or saline with 1:1 allocation. Measurements and Main Results All patients were evaluated using a modified American Fertility Society (mAFS) scoring system for the incidence, extent, and severity of pre-existing and postoperative adhesions at the 10 anatomic sites of ovaries/tubes and at the expanded 23 or 24 anatomic sites throughout the abdominopelvic cavity by laparoscopy. A total of 215 randomized patients were treated with either saline solution (108 of 108) or NCH gel (107 of 108), composing the full analysis set (FAS), and 196 patients (94 of 108 in the saline control group and 102 of 108 in the NCH gel group) completed the entire study, composing the per protocol set (PPS). The postoperative incidence of moderate or severe adhesions evaluated at the 10 sites (the primary endpoint for efficacy) was 27.7% in the control group and 9.8% in the NCH gel group, a difference of 14.4% (95% confidence interval [CI], 2.6%–20.6%) in the PPS, and 37.0% in the control group and 14.0% in the NCH gel group, a difference of 20.0% (95% CI, 8.9%–26.8%) in the FAS. The postoperative incidence of moderate or severe adhesions evaluated at the 24 sites was also significantly lower in the NCH gel group compared with the control group (5.9% vs 14.9%; p = .036) in the PPS. Also in the PPS, the NCH gel group had significantly lower postoperative adhesion scores of severity, extent, and mAFS: 60.0%, 50.8%, and 76.9%, respectively (median scores of the 10 sites; p = .002) and 48.5%, 50.0%, and 72.2% (median scores of the 24 sites; p = .001) lower than those recorded in the control group. No serious adverse events were observed, and the safety profile of NCH gel was comparable to that of saline control. Conclusion This study demonstrates that NCH gel is safe and significantly reduces adnexal adhesion formation and global adhesion formation throughout the abdominopelvic cavity after gynecologic laparoscopic surgery.

The basic helix–loop–helix (bHLH) transcription factors possess crucial functions in cell proliferation, determination, differentiation, cell cycle maintenance and homeostasis or stress response pathways. Since a few juvenile hormone analogues such as hydroprene, methoprene and pyriproxyfen targeting a bHLH member Met are already registered for pest management, there is a potential to develop more insecticides targeting various bHLHs. The identification of bHLH members is the first step. Based on the transcriptome and the genome of the Colorado potato beetle Leptinotarsa decemlineata, the most important pest in potato, 49 bHLH members were identified. All LdbHLH members were defined by their names and families according to various phylogenetic analyses with bHLH homologues of Drosophila melanogaster, Apis mellifera, Bombyx mori and Tribolium castaneum. Among these LdbHLHs, 17, 10, 10, 1, 10 and 1 members belonged to A, B, C, D, E and F high-order groups, respectively. The results would provide useful background information for future studies on functions of bHLH proteins in the regulation of L. decemlineata development. Moreover, the bHLHs could serve as potential insecticide targets. These proteins could be used in small molecule screen, or in the development of RNAi-based pest management methods.

The R2R3-MYB protein SlAN2 has long been thought to be a positive regulator of anthocyanin accumulation. To investigate the role of SlAN2, we have previously overexpressed the gene in tomato. In this work, we analysed physiological characters of the transgenic plants during the fruit ripening. We show that fruits of transformants overexpressing SlAN2 displayed an orange colour, fast softening and elevated ethylene production. Overexpression of SlAN2 resulted in reduction of carotenoid levels via alteration of flux through the carotenoid pathway, elevated ethylene synthesis mainly via upregulation of ethylene biosynthesis genes, and early softening of fruits. We also found that the transcript level of SlRIN, an important ripening-related gene, was up-regulated in transgenic fruits. These results suggest that SlAN2 acts as an important regulator of fruit ripening.

LeAN2 is an anthocyanin-associated R2R3-MYB transcription factor, but little is known about its function in imparting thermo-tolerance to higher plants. To examine the function of LeAN2 in the regulation of heat stress in tomato, LeAN2 was isolated and transgenic tomato plants were obtained. Overexpression of LeAN2 under the control of the CaMV35S promoter in tomato induced the up-regulation of several structural genes in the anthocyanin biosynthetic pathway as well as anthocyanin accumulation in transgenic tomato plants. Transgenic tomato plants showed enhanced tolerance to heat stress by maintaining higher fresh weight (FW), net photosynthetic rate (Pn) and maximal photochemical efficiency of photosystem II (PSII) (Fv/Fm) compared with wild-type (WT) plants. Furthermore, transgenic plants showed higher non-enzymatic antioxidant activity, lower levels of reactive oxygen species (ROS), and higher contents of D1 protein than that in WT plants under heat stress. These results indicate that LeAN2 had an important function in heat stress resistance.

Juvenile hormone III (JH III) plays primary roles in regulation of metamorphosis, reproduction and diapause in Leptinotarsa decemlineata, a notorious defoliator of potato. The neurosecretory cell-borne substance(s) negatively affects the final two steps in JH biosynthesis, catalyzed respectively by an epoxidase CYP15A1 and a juvenile hormone acid methyltransferase (JHAMT). In a few insect species other than L. decemlineata, the inhibitory substance is allatostatin (AS) neuropeptide. In this study, two putative AS genes encoding LdAS-C and LdAS-B precursors were cloned. Both LdAS-C and LdAS-B were expressed in the egg, larvae, pupae and adults, and highly expressed in the brain and the gut. Dietary introduction of double-stranded RNAs (dsRNAs) targeting LdAS-C and LdAS-B successfully knocked down respective target genes. Ingestion during 3 and 6 consecutive days of dsLdAS-C significantly increased the LdJHAMT mRNA levels by 3.8 and 9.9 fold respectively. In contrast, ingestion of dsLdAS-B only slightly increased the LdJHAMT expression level by 1.1 and 1.7 fold. Moreover, after one, two and three days' ingestion of dsLdAS-C, the relative JH levels in the hemolymph of treated larvae were 2.5, 4.2 and 1.9 fold higher than those in control beetles. Furthermore, ingestion of dsLdAS-C and dsLdAS-B significantly affected larval growth and delayed larval development. Thus, we provide a line of experimental evidence in L. decemlineata to support the concept that AS-C acts as an allatostatin and inhibit JH biosynthesis.

NAC (NAM, ATAF1,2, and CUC2) transcription factors play an important role in the responses of plants to various environmental stresses. To investigate the function of SlNAC1, which was found to be a member of the ATAF subfamily in tomato (Solanum lycopersicum L.) plants under heat stress conditions, transgenic tomato plants were generated using an antisense technology. After a treatment at 40 °C for 48 h, in comparison with wild-type (WT) plants, the transgenic plants were severely wilted and exhibited a lower net photosynthetic rate and a maximal photochemical efficiency of photosystem II. Moreover, the transgenic plants displayed a higher ion leakage and malondialdehyde content and a lower proline content. The content of reactive oxygen species (superoxide anion radicals and hydrogen peroxide) were higher, and activities of ascorbate peroxidase and superoxide dismutase lower in the transgenic plants than in the WT plants. The transgenic plants also exhibited a lower accumulation of the transcripts of some heat shock protein genes (Hsp70, Hsp90, sHsp17.4, and sHsp17.6). All of these results suggest that the suppression of SlNAC1 could obviously reduce heat resistance in the tomato plants, and this indicates that SlNAC1 played an important role in the thermal tolerance of the tomato plants.

Background: The aim of this study was to compare the safety and survival outcomes of early stage cervical cancer patients treated by laparoscopically assisted radical vaginal hysterectomy (LARVH) versus abdominal radical hysterectomy (ARH). Methods: Since March 2008 to July 2012, the patients with early stage cervical cancer undergoing LARVH or ARH in Beijing hospital have been entered into this study. Statistical analysis used Statistical Product and Service Solutions (SPSS) and significance was defined as P

Chilling stress limits the productivity and geographical distribution of many organisms throughout the world. In plants, the small heat shock proteins (sHSPs) belong to a group of proteins known as chaperones. The sweet pepper (Capsicum annuum L.) cDNA clone CaHSP22.5, which encodes an endoplasmic reticulum-located sHSP (ER-sHSP), was isolated and introduced into tobacco (Nicotiana tabacum L.) plants and Escherichia coli. The performance index and the maximal efficiency of PSII photochemistry (Fv/Fm) were higher and the accumulation of H2O2 and superoxide radicals (O2–) was lower in the transgenic lines than in the untransformed plants under chilling stress, which suggested that CaHSP22.5 accumulation enhanced photochemical activity and oxidation resistance. However, purified CaHSP22.5 could not directly reduce the contents of H2O2 and O2– in vitro. Additionally, heterologously expressed recombinant CaHSP22.5 enhanced E. coli viability under oxidative stress, helping to elucidate the cellular antioxidant function of CaHSP22.5 in vivo. At the same time, antioxidant enzyme activity was higher, which was consistent with the lower relative electrolyte conductivity and malondialdehyde contents of the transgenic lines compared with the wild-type. Furthermore, constitutive expression of CaHSP22.5 decreased the expression of other endoplasmic reticulum molecular chaperones, which indicated that the constitutive expression of ER-sHSP alleviated endoplasmic reticulum stress caused by chilling stress in plants. We hypothesise that CaHSP22.5 stabilises unfolded proteins as a chaperone and increases the activity of reactive oxygen species-scavenging enzymes to avoid oxidation damage under chilling stress, thereby suggesting that CaHSP22.5 could be useful for improving the tolerance of chilling-sensitive plant types.

Chilling stress severely affects the growth, development and productivity of crops. Chloroplast, a photosynthesis site, is extremely sensitive to chilling stress. In this study, the functions of a gene encoding a cold-regulated protein (SlCOR413IM1) under chilling stress were investigated using sense and antisense transgenic tomatoes. Under chilling stress, SlCOR413IM1 expression was rapidly induced and the sense lines exhibited better growth state of seedlings and grown tomato plants. Overexpression of SlCOR413IM1 alleviated chilling-induced damage to the chloroplast membrane and structure, whereas suppression of SlCOR413IM1 aggravated the damage to chloroplast. Moreover, the net photosynthetic rate (Pn), maximum photochemical efficiency of photosystem II (PSII) (Fv/Fm), actual photochemical efficiency of PSII (ΦPSII) and the activities of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and stromal fructose-1, 6-bisphosphatase (sFBPase) were higher in the sense lines than those in the antisense lines. Hence, the inhibition of photosynthetic capacity was less severe in the sense lines but more severe in the antisense lines compared with that in wild-type (WT) plants. Taken together, overexpression of SlCOR413IM1 enhanced the chilling stress tolerance, whereas suppression of this gene increased the chilling sensitivity of tomato plants.

Hormone receptor 4 (HR4) is involved in the regulation of 20-hydroxyecdysone (20E) biosynthesis and the mediation of 20E signaling during larval-pupal transition in a holometabolan Drosophila melanogaster , whereas it acts as a repressor in 20E-responsive transcriptional cascade in a hemimetabolan, Blattella germanica . Here we characterized two HR4 splicing variants, LdHR4X1 and LdHR4X2 , in a coleopteran Leptinotarsa decemlineata . LdHR4X1 was highly expressed in the prothoracic gland and epidermis while LdHR4X2 was abundantly transcribed in the nervous system. In vivo results showed that both prothoracicotropic hormone and 20E pathways transcriptionally regulated LdHR4 , in an isoform-dependent pattern. RNA interference of LdHR4 at the final (fourth) larval instar, in contrast to the second- and third-instar periods, enhanced the expression of two ecdysteroidogenesis genes, increased 20E titer, upregulated transcription of five 20E-response genes, and reduced the mRNA level of Fushi tarazu-factor 1 ( FTZ-F1 ). As a result, the fourth-instar LdHR4 RNAi larvae exhibited accelerated development and reduced body weight. Moreover, knockdown of LdHR4 at the fourth instar resulted in larval lethality and impaired pupation. Feeding of pyriproxyfen (a mimic of juvenile hormone) or silencing of a juvenile hormone degrading enzyme gene restored the normal course of ecdysteroidogenesis, duration of larval development, and body weight in fourth-instar LdHR4 RNAi larvae. The treatment partially suppressed the larval mortality but not the failure to pupate. The dual role of HR4 during larval-pupal metamorphosis appears to be evolutionarily conserved among holometabolans.

Chilling is one of the most serious environmental stresses that disrupt the metabolic balance of cells and enhance the production of reactive oxygen species (ROS). Light harvesting complex (LHC) proteins had a function in dissipating excess excitation energy and eliminating ROS to maintain the normal physiological function of cells. A tomato (Lycopersicon esculentum) LHC antenna protein gene (LeLhcb2) was isolated. The LeLhcb2-green fluorescent protein (GFP) fusion protein was targeted to the chloroplast of Arabidopsis mesophyll protoplast. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis indicated that the expression of LeLhcb2 was markedly abundant in leaves and was induced by chilling (4 °C). qRT-PCR analysis and western blot confirmed that the sense gene LeLhcb2 was transferred into tobacco genome and overexpressed. Under chilling stress, the transgenic plants showed not only better growth, higher fresh weight, chlorophyll content, but also lower malondialdehyde (MDA) accumulation and relative electrical conductivity (REC), compared with the wild type (WT). The maximal photochemical efficiency of PSII (Fv/Fm), non-photochemical quenching (NPQ) and D1 protein content were also higher in the transgenic plants. Furthermore, the relatively lower hydrogen peroxide (H2O2) and superoxide radical (O2(-)) levels in the sense plants were not considered to due to the higher activity of ascorbate peroxidase (APX) and superoxide dismutase (SOD). These results suggested that the overexpression of LeLhcb2 had a key function in alleviating photo-oxidation of PSII and enhanced transgenic tobacco tolerance to chilling stress.

CBF3, a known cold-inducible gene that encodes a transcription factor, was isolated from Arabidopsis thaliana and introduced into the potato (Solanum tuberosum cv. 'luyin NO.1') under the control of the CaMV35S promoter or the rd29A promoter. Our results revealed that temperature of 40 °C or higher can significantly induce AtCBF3 expression. After heat stress, the net photosynthetic rate (Pn ), the maximal photochemical efficiency of photosystem II (PSII) (Fv /Fm ) and the accumulation of the D1 protein were higher in the transgenic lines than in the wild-type (WT) line. Moreover, compared with the WT line, O2 (●-) and H2 O2 accumulation in the transgenic lines were reduced. A Q-PCR assay of a subset of the genes involved in photosynthesis and antioxidant defence further verified the above results. Interestingly, under heat stress conditions, the accumulation of heat-shock protein 70 (HSP70) increased in the WT line but decreased in the transgenic lines. These results suggest that potato plants ectopically expressing AtCBF3 exhibited enhanced tolerance to high temperature, which is associated with improved photosynthesis and antioxidant defence via induction of the expression of many stress-inducible genes. However, this mechanism may not depend upon the regulatory pathways in which HSP70 is involved.

The overexpression of tomato GDP- l -galactose phosphorylase gene enhanced tolerance to chilling stress and reduced photoinhibition of photosystems I and II in transgenic tobacco. Chilling stress is a crucial factor that limits the geographical distribution and yield of chilling-sensitive plants. Ascorbate (AsA) protects plants by scavenging reactive oxygen species and reduces photoinhibition by promoting the conversion of violaxanthin to zeaxanthin in the xanthophyll cycle to dissipate excess excitation energy. Possible mechanisms of AsA for plant photoprotection under chilling stress were investigated by isolating the tomato GDP-l-galactose phosphorylase gene (SlGGP) and producing transgenic tobacco plants with overexpression of SlGGP. The transgenic plants subjected to chilling stress accumulated less H2O2, demonstrated lower levels of ion leakage and malondialdehyde, and acquired higher net photosynthetic rate, higher maximum photochemical efficiency of PSII, and higher D1 protein content compared with the wild-type (WT) plants. The transgenic plants subjected to chilling stress also showed higher GDP-l-galactose phosphorylase activity, increased AsA content as well as ascorbate peroxidase and oxidizable P700 activities than WT plants. Thus, SlGGP overexpression is crucial in promoting AsA synthesis and alleviating photoinhibition of two photosystems.

LeAN2 encoding an anthocyanin-associated R2R3-MYB transcription factor was isolated from tomato. The expression of LeAN2 in tomato was induced by low temperature and oxidative stress. Green fluorescent protein was fused to LeAN2 and the complex was expressed transiently in onion epidermal cells. Green fluorescence was observed only in the nucleus. Overexpression of LeAN2 under the control of the CaMV35S promoter in tobacco induced expression of several anthocyanin biosynthetic genes and the content of anthocyanin was markedly higher in transgenic tobacco compared with wild type plants. Transgenic tobaccos conferred tolerance to chilling stress by maintaining a higher chlorophyll content, net photosynthetic rate, and maximal photochemical efficiency of PS II compared to the wild type plants. Furthermore, the transgenic plants showed lower ion leakage, a lower content of reactive oxygen species, and a higher content of non-enzymatic antioxidans under the chilling stress. They also showed an enhanced resistance to the oxidative stress induced by methyl viologen based on a decreased chlorophyll content loss, lower ion leakage, and an enhanced maximal photochemical efficiency of PS II. These results indicate that overexpression of LeAN2 resulted in an increased anthocyanin accumulation and enhanced resistance to the chilling and oxidative stresses in transgenic tobacco.

The roles of a tomato (Lycopersicon esculentum) chloroplast-targeted DnaJ protein (LeCDJ1) were investigated using wild-type (WT) and sense transgenic tomatoes. The LeCDJ1 expression was upregulated by 38 °C, 42 °C, 45 °C, NaCl, PEG, methyl viologen (MV) and hydrogen peroxide (H2O2), but not by 30 °C and 35 °C. Meanwhile, LeCDJ1 was involved in the response of plants to abscisic acid (ABA). Under heat stress, the sense plants showed better growth, higher chlorophyll content, lower malondialdehyde (MDA) accumulation and relative electrical conductivity (REC), and also less PSII photoinhibition than WT. Interestingly, the sense plants treated with streptomycin (SM), an inhibitor of organellar translation, still showed higher maximum photochemistry efficiency of PSII (Fv/Fm) and D1 protein levels than the SM-untreated WT, suggesting that the protective effect of LeCDJ1 on PSII was, at least partially, independent of D1 protein synthesis. Furthermore, the relatively lower superoxide radical (O2(•-)) and H2O2 levels in the sense plants were considered to be due to the higher ascorbate peroxidase (APX) and superoxide dismutase (SOD) activity, which seemed unlikely dependent on their transcription level. These results indicated that LeCDJ1 overexpression facilitated heat tolerance in transgenic tomatoes.

ICE1 (inducer of CBF expression 1), a MYC-type bHLH transcription factor, is an important activator of CBF3/DREB1A for regulating cold signaling and stress tolerance. In this study, we isolated the novel ICE1-like gene SlICE1a from tomato which contains the conserved bHLH domain, an S-rich motif, and ACT-domain. It is localized in the nucleus and harbors transcription-activating activity in the N-terminal. In addition, the SlICE1a transcript is slightly upregulated by cold stress, salt stress, and osmotic stress. SlICE1a overexpression in tobacco enhances the induction of CBF/DREB and their target genes, consequently increasing the levels of proline, soluble sugars, and late embryogenesis abundant (LEA) proteins, and enhancing tolerance to cold stress, osmotic stress, and salt stress. SlICE1a functions in abiotic stress responses by regulating the expression of stress-tolerant genes, and is thus beneficial for crop improvement.

A novel tomato chloroplast-targeted DnaJ protein, LeCDJ1 was found to contribute to the maintenance of photosystem II under chilling stress and this maintenance effect was, at least partially, independent of D1 protein synthesis, DnaJ proteins act as essential molecular chaperones in protein homeostasis and protein complex stabilization under stress conditions. The roles of a tomato (Lycopersicon esculentum) chloroplast-targeted DnaJ protein (LeCDJ1), whose expression was upregulated by treatment at 4 and 42 °C, and with high light, NaCl, polyethylene glycol, and H2O2, were investigated here using sense and antisense transgenic tomatoes. The sense plants exhibited not only higher chlorophyll content, fresh weight and net photosynthetic rate, but also lower accumulation of reactive oxygen species and membrane damage under chilling stress. Moreover, the maximal photochemistry efficiency of photosystem II (PSII) (F v/F m) and D1 protein content were higher in the sense plants and lower in the antisense plants, and the photoinhibitory quenching was lower in the sense plants and higher in the antisense plants, suggesting that the inhibition of PSII was less severe in the sense plants and more severe in the antisense plants compared with the wild type. Furthermore, the PSII protein complexes were also more stable in the sense plants. Interestingly, the sense plants treated with streptomycin (SM), an inhibitor of organellar translation, still showed higher F v/F m, D1 protein content and PSII stability than the SM-untreated antisense plants. This finding suggested that the protective effect of LeCDJ1 on PSII was, at least partially, independent of D1 protein synthesis. Furthermore, chloroplast heat-shock protein 70 was identified as the partner of LeCDJ1. These results indicate that LeCDJ1 has essential functions in maintaining PSII under chilling stress.

Chilling is one of the most serious environmental stresses that disrupt the metabolic balance of cells and enhance the production of reactive oxygen species (ROS). Lutein plays important roles in dissipating excess excitation energy and eliminating ROS to maintain the normal physiological function of cells. A tomato carotenoid epsilon-ring hydroxylase gene (LeLUT1) was isolated, and the LeLUT1-GFP fusion protein was localized in the chloroplast of Arabidopsis mesophyll protoplast. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis indicated that the expression of LeLUT1 was the highest in the leaves and was down-regulated by various abiotic stresses in tomato. The transgenic tobacco plants overexpressing LeLUT1 had higher lutein content, which was decreased in cold condition. Under chilling stress, the non-photochemical quenching (NPQ) values were higher in the transgenic plants than in the wild type (WT) plants. Compared with the WT plants, the transgenic plants showed lower levels of hydrogen peroxide (H2O2), superoxide radical (O2(·-)), relative electrical conductivity, and malondialdehyde content (MDA), and relatively higher values of maximal photochemical efficiency of photosystem II (Fv/Fm), oxidizable P700 of PSI, and net photosynthetic rate (Pn). Therefore, the transgenic seedlings were less suppressed in growth and lost less cotyledon chlorophyll than the WT seedlings. These results suggested that the overexpression of LeLUT1 had a key function in alleviating photoinhibition and photooxidation, and decreased the sensitivity of photosynthesis to chilling stress.

Uninterrupted wide range operations are salient features of the process industries. Characteristics including nonlinearity, time-delay, and inertia, of industrial control loops are always significantly changed with the working conditions. To qualify the nonlinear degree, a nonlinearity measure based on the minimum variance lower bound ratio is presented in this paper. This measure belongs to the data-driven class, and can be applied to Hammerstein structure, Wiener structure and Wiener–Hammerstein structure, whether the controller is linear or nonlinear. The effectiveness and consistency of this measure are illustrated through five simulation tests. An industrial case in the fossil fuel power generation process is studied to confirm the practicability of the proposed measure.

We studied how tomato (Lycopersicon esculentum Mill.) chloroplast omega-3 fatty acid desaturase gene (Lefad7) overexpression enhanced low-temperature (LT) tolerance in transgenic tomato plants. In these plants, the content of linolenic acid (18:3) markedly increased and, correspondingly, the content of linoleic acid (18:2) decreased. Similar changes were found after 6 h under LT (4°C) treatment. Under LT stress, wild type (WT) tomato plants showed a much greater increase in relative electrolyte leakage and malondialdehyde (MDA) contents compared with transgenic plants. Transgenic plants exhibited higher activities of antioxidative enzymes and a lower content of reactive oxygen species (ROS). Transgenic plants maintained a relatively higher level of the net photosynthetic rate (PN) and chlorophyll (Chl) content than WT plants under LT stress. Taken together, we suggested that overexpression of Lefad7 enhanced LT tolerance by changing the composition of membrane lipids in tomato plants, with the increased content of trienoic fatty acids and reduced content of dienoic fatty acids that led to series of physiological alterations.

Unreasonable sizes of grooves would aggravate the hot air recirculation and improve the air inlet temperature of outdoor units, which would result in a degradation of the energy efficiency ratio (EER) of air conditioner. This study used controlling variables method to design 40 kinds of working conditions by changing the distance from outdoor unit to each wall as well as discussed the change rules of the air inlet temperature of outdoor unit and EER. Finally, it is concluded by the analysis for experimental data that the influence of change in width or height of grooves on the heat dispersion performance of outdoor unit is significant, but that of change in depth of grooves is slight.

To accomplish consistent, long-term, integrated management (IPM) of the Colorado potato beetle, Leptinotarsa decemlineata (Say), research assessing the potential of novel, IPM-compatible insecticides is essential. Novaluron is a potent benzoylurea insecticide. In the present paper, we found that novaluron ingestion by the fourth-instar larvae inhibited foliage consumption, reduced larval fresh weight, and delayed development period, in a dose dependent manner. Most of the resulting larvae fail to pupate, and died at prepupae stage, with larvicidal activity comparable with those of cyhalothrin and spinosad but lower than those of fipronil and abamectin. Moreover, many surviving pupae that fed novaluron failed to emerge as adults, in a dose dependent pattern. Furthermore, feeding of novaluron significantly decreased chitin contents in body carcass (without midgut) and integument specimen, whereas the chitin concentration in the midgut peritrophic matrix was not affected. Furthermore, uridine diphosphate-N-acetylglucosamine-pyrophosphorylase gene (LdUAP1) and chitin synthase Aa (LdChSAa), which were mainly responsible for chitin biosynthesis in ectodermally-derived tissues, were surpressed and activated respectively after novaluron ingestion. Therefore, novaluron is an effective benzoylurea insecticide to L. decemlineata fourth-instar larvae. It inhibited chitin biosynthesis in ectodermally-derived tissues, disrupted ecdysis, impaired pupation and adult emergence, and led to death in juvenile life stages.

High temperature has become a major abiotic stress that limits crop productivity. Heat shock transcription factors (HSFs) and heat shock proteins (HSPs) play important roles in enhancing thermotolerance of plants. SUMOylation is an important post-translational modification in regulating cellular functions in eukaryotes. SIZ1, a well-characterized SUMO E3 ligase, mediates the process of SUMOylation. In this study, SUMO conjugations were clearly induced by high temperature. Overexpression of SIZ1 SUMO E3 ligase (SlSIZ1) in tomato could enhance the tolerance to heat stress in tomato. The RNA interference (RNAi) plants were more wilted than the wild type with heat treatment. Under heat stress, SlSIZ1 could decrease the accumulation of reactive oxygen species (ROS) and induce some genes of HSF and HSP transcription. Furthermore, overexpression of SlSIZ1 could increase the level of Hsp70 under high temperature. Yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assays showed that SlSIZ1 could interact with SlHsfA1 to mediate the SUMOylation of SlHsfA1 and consequently enhance thermotolerance of tomato. In conclusion, overexpression of SlSIZ1 enhanced heat tolerance by regulating the activities of HsfA1 and increasing the content Hsp70.

Drosophila cap ‘n’ collar isoform C (CncC) and Kelch-like ECH associated protein 1 (Keap1) regulate metamorphosis by transcriptional control of a subset of genes involved in ecdysteroidogenesis, 20-hydroxyecdysone (20E) signaling, and juvenile hormone (JH) degradation. In the present paper, we found that prothoracicotropic hormone signal was required for the activation of LdCncC and LdKeap1 in Leptinotarsa decemlineata. Moreover, RNA interference of LdCncC or LdKeap1 in the fourth-instar larvae delayed development. As a result, the treated larvae obtained heavier larval and pupal fresh weights and had larger body sizes than the controls. Furthermore, knockdown of LdCncC or LdKeap1 significantly reduced the mRNA levels of four ecdysone biosynthetic genes (Ldspo, Ldphm, Lddib and Ldsad), lowered 20E titer and decreased the transcript levels of five 20E response genes (LdEcR, LdUSP, LdE75, LdHR3 and LdFTZ-F1). However, the expression of two JH epoxide hydrolase genes and JH contents were not affected in the LdCncC and LdKeap1 RNAi larvae. Dietary supplementation with 20E shortened the developmental period to normal length, rescued the larval and pupal body mass rises, and recovered or even overcompensated the expression levels of the five 20E response genes in either LdCncC or LdKeap1 RNAi hypomorphs. Therefore, LdCncC/LdKeap1 signaling regulates several ecdysteroidogenesis genes, and consequently 20E pulse, to modulate the onset of metamorphosis in L. decemlineata.

Tomato (Solanum lycopersicum cv. 'Moneymaker') was transformed with the choline oxidase gene codA from Arthrobacter globiformis, which was modified to allow for targeting to both chloroplasts and the cytosol. Glycine betaine (GB) was accumulated in transformed plants, while no detectable GB was found in wild-type (WT) plants. Compared to WT plants, transgenic lines showed significantly higher photosynthetic rates (Pn) and antioxidant enzyme activities and lower reactive oxygen species (ROS) accumulation in the leaves when exposed to salt stress. Furthermore, compared with WT plants, K+ efflux decreased and Na+ efflux increased in roots of transgenic plants under salt stress; resulted in lower Na+/K+ ratios in transgenic lines. The exogenous application of GB also significantly reduced NaCl-induced K+ efflux and increased Na+ efflux in WT plants. A qRT-PCR assay indicated that GB enhanced NaCl-induced expression of genes encoding the K+ transporter, Na+/H+ antiporter, and H+-ATPase. These results suggest that the enhanced salt tolerance conferred by codA in transgenic tomato plants might be due to the regulation of ion channel and transporters by GB, which would allow high potassium levels and low sodium levels to be maintained in transgenic plants under salt stress condition.

Plants are always exposed to abiotic and biotic stresses which can adversely affect their growth and development. As an important antioxidant, AsA plays a vital role in plant defence against damage caused by stresses. In this study, we cloned a tomato GDP-L-galactose phosphorylase-like (SlGGP-LIKE) gene and investigated its role in resistance to abiotic and biotic stresses by using antisense transgenic (AS) tomato lines. The AsA content in AS plants was lower than that in WT plants. Under chilling stress, the growth of AS plants was inhibited significantly, and they yielded higher levels of ROS, REC and MDA but demonstrated weaker APX activity than that shown by WT plants. Additionally, the declined values of Pn, Fv/Fm, oxidisable P700, and D1 protein content of PSII in AS lines were significant. Furthermore, the effect on xanthophyll cycle of AS plants was more severe than that on WT plants, and the ratio of zeaxanthin (Z)/(V + A + Z) and (Z + 0.5 A)/(V + A + Z) in AS lines was lower than that in WT plants. In spite of chilling stress, under Pseudomonas syringae pv.tomato (Pst) DC3000 strain infection, AS plants showed lesser bacterial cell growth and dead cells than those shown by WT plants. This finding indicated that AS plants demonstrated stronger resistance against pathogenic infection. Results suggest that SlGGP-LIKE gene played an important role in plant defence against chilling stress and pathogenic infection.

Drought stress adversely affects plant growth, development, and productivity. Genes functioning in plant response to drought stress are essential for drought tolerance. In this study, SlCOR413IM1, a cold-regulated gene isolated from Solanum lycopersium, was transferred to Nicotiana tabacum to investigate its function under drought stress. The subcellular localisation of SlCOR413IM1-GFP fusion protein in Arabidopsis protoplasts suggested that SlCOR413IM1 is a chloroplast protein. Expression analyses revealed that SlCOR413IM1 responded to drought and cold stresses. Under drought stress, transgenic plants maintained the high maximum photochemical efficiency, net photosynthetic rate (Pn) and D1 protein content of photosystem II (PSII). Compared with wild-type (WT) plants, transgenic plants showed higher superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities and proline and soluble sugar content, which reduced reactive oxygen species (ROS) generation. However, the high SOD and APX activities in transgenic plants were independent of their transcription levels. Moreover, the transgenic plants exhibited better seed germination, water status and survival, as well as lower malondialdehyde (MDA) content and relative electrical conductivity (REC) than WT plants under drought stress. Taken together, these data demonstrated that overexpression of SlCOR413IM1 enhanced drought stress tolerance in transgenic tobacco.

Low temperature has a negative impact on plant cells and results in the generation of reactive oxygen species (ROS). In order to study the role of ascorbate under chilling stress, the response of an ascorbate-deficient Arabidopsis thaliana mutant vtc2-1 to low temperature (2°C) was investigated. After chilling stress, vtc2-1 mutants exhibited oxidative damage. An increase in the H2O2 generation and the production of thiobarbituric acid reactive substances (TBARS), and a decrease in chlorophyll content, the maximal photochemical efficiency of PSII (Fv/Fm) and oxidizable P700 were also noted. The ratio of ascorbate/dehydroascorbate and reduced glutathione/oxidzed glutathione in the vtc2-1 mutants were reduced, compared with the wild type (WT) plants. The activities of antioxidant enzymes, such as catalase (CAT) and ascorbate peroxidase (APX), and soluble antioxidants were lower in the vtc2-1 mutants than those in WT plants. These results suggested that the ascorbate-deficient mutant vtc2-1 was more sensitive to chilling treatment than WT plants. The low temperature-induced oxidative stress was the major cause of the decrease of PSII and PSI function in the vtc2-1 mutants. Ascorbate plays a critical role of defense without which the rest of the ROS defense network is unable to react effectively.

Photosynthesis is a well-established source of reactive oxygen species (ROS) in plants particularly under chilling stress. Ascorbate peroxidase (APXs) plays an important role in the anti-oxidant system by utilizing AsA as specific electron donor to reduce H 2 O 2 to water. In order to investigate the possible mechanisms of ascorbate peroxidsae (APX) in photoprotection under chilling stress, a tomato ( Lycopersicon esculentum Mill.) thylakoidal ascorbate peroxidase gene ( LetAPX ) was isolated and antisense transgenic tomato plants were produced. Under chilling stress, transgenic plants accumulated more H 2 O 2 , and showed higher levels of ion leakage and malondialdehyde (MDA), lower net photosynthetic rate (Pn), lower maximal photochemical efficiency of PSII (Fv/Fm) and less content of D1 protein compared with wild type (WT) plants. On the other hand, after chilling stress, transgenic plants showed higher reduced ascorbate (AsA) and activities of catalase (CAT) and superoxide dismutase (SOD) than those in WT plants, and the expression of several known stress-responsive and antioxidative genes was also higher at the end of chilling treatment. These results suggested that the suppression of LetAPX gene induced compensatory anti-oxidant mechanisms in tomato, and inactivation of tAPX may have a regulatory role in facilitating redox signaling pathways under chilling stress. Furthermore, transient increases in ROS levels also have a vital role in stress signaling and thereby in the survival of plants under chilling conditions.

Zeaxanthin (Z) has a role in the dissipation of excess excitation energy by participating in non-photochemical quenching (NPQ) and is essential in protecting the chloroplast from photooxidative damage. To investigate the physiological effects and functional mechanism of constitutive accumulation of Z in the tomato at salt stress-induced photoinhibition and photooxidation, antisense-mediated suppression of zeaxanthin epoxidase transgenic plants and the wild-type (WT) tomato were used. The ratio of Z/(V + A + Z) and (Z + 0.5A)/(V + A + Z) in antisense transgenic plants were maintained at a higher level than in WT plants under salt stress, but the value of NPQ in WT and transgenic plants was not significantly different under salt stress. However, the maximal photochemical efficiency of PSII (Fv/Fm) and the net photosynthetic rate (Pn) in transgenic plants decreased more slowly under salt stress. Furthermore, transgenic plants showed lower level of hydrogen peroxide (H(2)O(2)), superoxide anion radical (O(2)(•-)) and ion leakage, lower malondialdehyde content. Compared with WT, the content of D1 protein decreased slightly in transgenic plants under salt stress. Our results suggested that the constitutive accumulation of Z in transgenic tomatoes can alleviate salt stress-induced photoinhibition because of the antioxidant role of Z in the scavenging quenching of singlet oxygen and/or free radicals in the lipid phase of the membrane.

The effects of inhibition of mitochondrial alternative oxidase (AOX) respiratory pathway on photosynthetic apparatus in Rumex K-1 leaves were studied. Under high irradiance, the inhibition of AOX pathway caused over-reduction of photosystem (PS) 2 acceptor side, a decrease in the energy transfer in the PS 2 units, damage of donor side of PS 2 and decrease in pool size of electron acceptors. The inhibition of AOX pathway also decreased photosynthetic performance index (PIABS), actual photochemical efficiency (ΦPS2), photochemical quenching (qP) and photosynthetic O2 evolution rate. The results demonstrate that mitochondrial AOX pathway plays a vital role in photoprotection of photosynthetic apparatus.

Photosynthesis provides a strong reducing power and a high risk for generation of reactive oxygen species (ROS) particularly under chilling stress. Ascorbate peroxidases (APXs) reduce H(2)O(2) to water and play an important role in the antioxidant system of plants. Though thylakoid ascorbate peroxidase (tAPX) has been thought to be key regulator of intracellular levels of H(2)O(2), its physiological significance in the response to chilling stress is still under discussion. To study the contribution of tAPX to the ROS scavenging, a tomato thylakoidal ascorbate peroxidase gene (LetAPX) was isolated and transgenic tomatoes were obtained. The LetAPX-GFP fusion protein was targeted to chloroplast in Arabidopsis mesophyll protoplast. RNA blotting analysis revealed that the LetAPX transcript expression was up-regulated by chilling, high light, exogenous salicylic acid (SA) and methyl viologen (MV). Over expression of LetAPX in tomatoes conferred tolerance to chilling stress by maintaining higher reduced glutathione (GSH) content, chlorophyll and APX activities compared with wild type (WT) plants. Furthermore, transgenic plants showed lower levels of hydrogen peroxide (H(2)O(2)) and ion leakage, lower malendialdehyde (MDA) content, higher net photosynthetic rate (Pn) and higher maximal photochemical efficiency of PSII (Fv/Fm). The oxidizable P700 decreased more obviously in WT than that in transgenic plants under chilling stress in low irradiance. The results suggested that over expression of tAPX played a key role both in alleviating photo inhibition of PSI and PSII and enhancing their tolerance to chilling stress.

RNA gel hybridization showed that the expression of monodehydroascorbate reductase (MDHAR) in the wild type (WT) tomato was decreased firstly and then increased under salt- and polyethylene glycol (PEG)-induced osmotic stress, and the maximum level was observed after treatment for 12 h. WT, sense transgenic and antisense transgenic tomato plants were used to analyze the antioxidative ability to cope with osmotic stresses. After salt stress, the fresh mass (FM) and height of sense transgenic lines were greater than those of antisense lines and WT plants. Under salt and PEG treatments, sense transgenic plants showed a lower level of hydrogen peroxide (H2O2) and malondialdehyde (MDA), a higher net photosynthetic rate (PN), and the maximal photochemical efficiency of PSII (Fv/Fm) compared with WT and antisense transgenic plants. Moreover, sense lines maintained higher ascorbate peroxidase (APX) activity than WT and antisense plants under salt- and PEG-induced osmotic stress. These results indicate that chloroplastic MDHAR plays an important role in alleviating photoinhibition of PSII by elevating ascorbate (AsA) level under salt- and PEG-induced osmotic stress.

Security of computer information system more and more aroused people’s attention, and information security assessment and computer system security model is closely related to information security model which is patricularly important. This article describes the security model of the characteristics and uses, and several security models are compared, these models were from a different perspective considering system security, through comparison Analysis, Establishment of information security model obtained several important aspects to consider.

We report here that disruption of function of the ω-3 FATTY ACID DESATURASE7 (FAD7) enhances plant defenses against aphids. The suppressor of prosystemin-mediated responses2 (spr2) mutation in tomato (Solanum lycopersicum), which eliminates the function of FAD7, reduces the settling behavior, survival, and fecundity of the potato aphid (Macrosiphum euphorbiae). Likewise, the antisense suppression of LeFAD 7 expression in wild-type tomato plants reduces aphid infestations. Aphid resistance in the spr2 mutant is associated with enhanced levels of salicylic acid (SA) and mRNA encoding the pathogenesis-related protein P4. Introduction of the Naphthalene/salicylate hydroxylase transgene, which suppresses SA accumulation, restores wild-type levels of aphid susceptibility to spr2. Resistance in spr2 is also lost when we utilize virus-induced gene silencing to suppress the expression of NONEXPRESSOR OF PATHOGENESIS-RELATED PROTEINS1 (NPR1), a positive regulator of many SA-dependent defenses. These results indicate that FAD7 suppresses defenses against aphids that are mediated through SA and NPR1. Although loss of function of FAD7 also inhibits the synthesis of jasmonate (JA), the effects of this desaturase on aphid resistance are not dependent on JA; other mutants impaired in JA synthesis (acx1) or perception (jai1-1) show wild-type levels of aphid susceptibility, and spr2 retains aphid resistance when treated with methyl jasmonate. Thus, FAD7 may influence JA-dependent defenses against chewing insects and SA-dependent defenses against aphids through independent effects on JA synthesis and SA signaling. The Arabidopsis (Arabidopsis thaliana) mutants Atfad7-2 and Atfad7-1fad8 also show enhanced resistance to the green peach aphid (Myzus persicae) compared with wild-type controls, indicating that FAD7 influences plant-aphid interactions in at least two plant families.

The purpose of this study was to explore how the mitochondrial AOX (alternative oxidase) pathway alleviates photoinhibition in Rumex K-1 leaves. Inhibition of the AOX pathway decreased the initial activity of NADP-malate dehydrogenase (EC 1.1.1.82, NADP-MDH) and the pool size of photosynthetic end electron acceptors, resulting in an over-reduction of the photosystem I (PSI) acceptor side. The over-reduction of the PSI acceptor side further inhibited electron transport from the photosystem II (PSII) reaction centers to the PSII acceptor side as indicated by an increase in V(J) (the relative variable fluorescence at J-step), causing an imbalance between photosynthetic light absorption and energy utilization per active reaction center (RC) under high light, which led to the over-excitation of the PSII reaction centers. The over-reduction of the PSI acceptor side and the over-excitation of the PSII reaction centers enhanced the accumulation of reactive oxygen species (ROS), which inhibited the repair of the photodamaged PSII. However, the inhibition of the AOX pathway did not change the level of photoinhibition under high light in the presence of the chloroplast D1 protein synthesis inhibitor chloramphenicol, indicating that the inhibition of the AOX pathway did not accelerate the photodamage to PSII directly. All these results suggest that the AOX pathway plays an important role in the protection of plants against photoinhibition by minimizing the inhibition of the repair of the photodamaged PSII through preventing the over-production of ROS.

A tomato (Lycopersicon esculentum Mill.) chloroplast glutathione reductase gene (LeGR) was isolated and antisense transgenic tomato lines were obtained. Under chilling stress, transgenic plants accumulated more H(2)O(2), leaked more electrolyte and showed lower net photosynthetic rate (Pn), maximal photochemical efficiency of PSII (Fv/Fm) and oxidizable P700 compared with wild-type (WT) plants. Transgenic seedlings were more suppressed in fresh-weight growth and lost more cotyledon chlorophyll. The decrease in the activity of ascorbate peroxidase (APX) was implied to be potentially relevant to the greater accumulation of H(2)O(2) in transgenic plants. Chilling treatment induced more decrease in the level of reducted glutathione (GSH) and redox ratio of glutathione in transgenic plants than in WT plants, but aroused more increase in GSSG in transgenic plants than in WT plants. Total glutathione displayed no change. Besides, chilling stress resulted in greater decreases in the level of reducted ascorbate (AsA), total ascorbate and redox ratio of ascorbate in transgenic plants than in WT plants, but led to equivalent degree of dehydroascorbate (DHA) increase in WT and transgenic plants. These assessments of glutathione-ascorbate cycle revealed that the decrease of glutathione reductase activity in transgenic plants affected glutathione regeneration, and consequently affected ascorbate regeneration and total ascorbate content. This resulted in a greater accumulation of H(2)O(2) and an enhanced sensitivity to chilling stress in transgenic plants. Moreover, a putative concept model of ecophysiological reaction was discussed.

Tomato (Lycopersicon esculentum cv. 'Moneymaker') was transformed with a codA gene, from Arthrobacter globiformis, for choline oxidase that had been modified to allow targeting to both chloroplasts and the cytosol. Glycinebetaine (GB) accumulated in seeds of transformed plants up to 1 µmol g(-1) dry weight (DW), while no detectable GB was found in wild-type (WT) seeds. The codA-transgenic seeds germinated faster and at higher frequency than WT seeds with high temperature treatment. After heat stress, levels of expression of a mitochondrial small heat-shock protein (MT-sHSP), heat-shock protein 70 (HSP70) and heat-shock cognate 70 (HSC70) were higher in transgenic seeds than in WT seeds during heat stress, and the accumulation of HSP70 was more prominent in codA-transgenic seeds than in WT seeds. Addition of GB to the germination medium or imbibition of seeds in a solution of GB enhanced the tolerance of WT seeds to high temperatures. WT seeds treated with exogenous GB also expressed heat-shock genes at elevated levels and accumulated more HSP70 than controls. Our results suggest that GB, either applied exogenously or accumulated in vivo in codA-transgenic seeds, enhanced the expression of heat-shock genes in and improved the tolerance to high temperature of tomato seeds during germination.

Genome-wide gene expression profiling was conducted by Solexa sequencing in order to gain insight into the transcriptome dynamics that are associated with salt stress of cotton seedlings. A total of 145,794 and 138,518 clean tags were generated from the control and salinity libraries, respectively. Of these, 75,500 (51.8%) and 72,077 (52.0%) tags were matched to the reference genes. The most differentially regulated tags with a log2ratio >2 or >−2 (P