The effects of 1-methylcyclopropene (MCP), sanitizer and their combination on ethylene action, microbial growth and storage life of fresh-cut cilantro were studied. Fresh cilantro was treated with 1.5 μL·L-1 MCP for 18 hours at 10 °C. The treated and nontreated cilantro leaves were cut and washed in water, chlorine, and mixed solution of sodium chlorite and citric acid (SANOVA). Samples were dried, packaged with 29.2μmol·kg-1 Pa s oxygen transmission rate films, and stored for 14 days at 5 °C. Results indicated that MCP affected respiration rate of fresh-cut cilantro and the headspace gas composition (O2 and CO2) of sample packages. The combined treatment had lower tissue electrolyte leakage and ethanol concentration, and delayed color changes during storage. SANOVA and the combination of MCP and SANOVA were effective in reducing aerobic microbial population and coliform population. Samples treated with MCP and SANOVA had good quality with high overall quality score at the end of storage.
Ji Gang Kim*, Yaguang Luo, Yang Tao, and Kenneth C. Gross
Raymond Fung*, Chien Wang, David Smith, Kenneth Gross, Yang Tao, and Meisheng Tian
Methyl salicylate (MeSA) and Methyl jasmonate (MeJA) treatments increased chilling resistance of light red tomato (Lycopersicon esculentum cv. Beefsteak) and extended shelf life and fresh-cut quality. We previously showed induction of AOX expression by low temperature and that induction of AOX transcript by MeSA and MeJA is correlated with resistance against chilling injury in peppers. Here, we investigate tomato, which is genetically closely related to peppers and belongs to the same Solanaceae family. In particular, we used four EST tomato clones of AOX from the public database that belong to two distinctly related families, 1 and 2 defined in plants. Three clones designated as LeAOX1a, 1b and 1c and the fourth clone as LeAOX2. Probes for these four genes were designed and Southern blotting done to confirm that they do not cross-hybridize. We will present data from Southern, Northern hybridization and RT-PCR to show: (1) gene copy number of each of these AOX members in the tomato genome; (2) gene-specific expression profiles in response to MeSA and MeJA in cold stored tomato; and (3) the relative transcript abundance of these four AOX genes.
Soohyun Kang, Yating Zhang, Yuqi Zhang, Jie Zou, Qichang Yang, and Tao Li
Ultraviolet-A (UV-A) is the main component of UV radiation in nature. However, its role on plant growth, to a large extent, remains unknown. In this study, tomato (Solanum lycopersicum ‘Beijing Cherry Tomato’) seedlings were cultivated in an controlled environment in which UV-A radiation was provided by UV-A fluorescent lamps (λmax = 369 nm) with a fluence rate of 2.28 W·m−2. The photoperiod of UV-A radiation was 0, 4, 8, and 16 hours, which corresponds to control, UV-A4, UV-A8, and UV-A16 treatments, respectively. The photosynthetic photon flux density (PPFD) was 220 μmol·m−2·s−1, which was provided by light-emitting diodes (LEDs) with a blue/red light ratio of 1:9, the photoperiod of PPFD was 16 hours. We showed that supplementing 8 and 16 hours of UV-A to visible radiation (400–700 nm) stimulated plant biomass production by 29% and 33%, respectively, compared with that of control. This resulted mainly from larger leaves (i.e., 22% and 31% in 8 and 16 hours UV-A, respectively), which facilitated light capture. Supplemental UV-A also enhanced photosynthetic capacity, as indicated by greater net photosynthesis rates in response to CO2 under saturating PPFD. Furthermore, the greatest stomatal conductance (g S) value was observed in UV-A16, followed by UV-A8, which correlated with the greater stomatal density in the corresponding treatments. Moreover, supplemental UV-A did not induce any stress, as the maximum quantum efficiency of photosynthetic system II (PSII) (F v/F m) remained ≈0.82 in all treatments. Similarly, chlorophyll content and leaf mass area (LMA) were also unaffected by UV-A radiation. Taken together, we conclude that supplementing reasonable levels of UV-A to visible radiation stimulates growth of indoor cultivated tomato seedlings.
Zhuang-Zhuang Liu, Tao Chen, Fang-Ren Peng, You-Wang Liang, Peng-Peng Tan, Zheng-Hai Mo, Fan Cao, Yang-Juan Shang, Rui Zhang, and Yong-Rong Li
Cytosine methylation plays important roles in regulating gene expression and modulating agronomic traits. In this study, the fluorescence-labeled methylation-sensitive amplified polymorphism (F-MSAP) technique was used to study variation in cytosine methylation among seven pecan (Carya illinoinensis) cultivars at four developmental stages. In addition, phenotypic variations in the leaves of these seven cultivars were investigated. Using eight primer sets, 22,796 bands and 950 sites were detected in the pecan cultivars at four stages. Variation in cytosine methylation was observed among the pecan cultivars, with total methylation levels ranging from 51.18% to 56.58% and polymorphism rates of 82.29%, 81.73%, 78.64%, and 79.09% being recorded at the four stages. Sufficiently accompanying the polymorphism data, significant differences in phenotypic traits were also observed among the pecan cultivars, suggesting that cytosine methylation may be an important factor underlying phenotypic variation. Hypermethylation was the dominant type of methylation among the four types observed, and full methylation occurred at higher levels than did hemimethylation in the pecan genomes. Cluster analysis and principal coordinate analysis (PCoA) identified Dice coefficients ranging from 0.698 to 0.778, with an average coefficient of 0.735, and the variance contribution rates of the previous three principal coordinates were 19.6%, 19.0%, and 18.2%, respectively. Among the seven pecan cultivars, four groups were clearly classified based on a Dice coefficient of 0.75 and the previous three principal coordinates. Tracing dynamic changes in methylation status across stages revealed that methylation patterns changed at a larger proportion of CCGG sites from the 30% of final fruit-size (30%-FFS) stage to the 70%-FFS stage, with general decreases in the total methylation level, the rate of polymorphism, and specific sites being observed in each cultivar. These results demonstrated that the F-MSAP technique is a powerful tool for quantitatively detecting cytosine methylation in pecan genomes and provide a new perspective for studying many important life processes in pecan.
Jun-Bo Yang, Hong-Tao Li, De-Zhu Li, Jie Liu, Lian-Ming Gao, De-Zhu Li, Lian-Ming Gao, and Jie Liu
The Himalayan yew, Taxus wallichiana Zucc., is an endangered species with a scatted distribution in the Eastern Himalayas and southwestern China. In the present study, 10 microsatellite markers from the genome of T. wallichiana were developed using the protocol of fast isolation by amplified fragment length polymorphism of sequences containing repeats (FIASCO). Polymorphism of each locus was assessed in 28 samples from four wild populations of the Himalayan yew. The allele number of the microsatellites ranged from two to five with an average of 2.9 per allele. The observed and expected heterozygosity varied from 0.00 to 1.00 and from 0.3818 to 0.7552, respectively. Cross-species amplification in another two yew species showed eight of them holding promise for sister species. Two of the 10 loci (TG126 and TC49) significantly deviated from Hardy-Weinberg expectations. No significant linkage disequilibrium was detected between the comparisons of these loci. These polymorphic microsatellite markers would be useful tools for population genetics studies and assessing genetic variations to establish conservation strategy of this endangered species.
Ahmad Hassan, Chen Qibing, Jiang Tao, Lv Bing-Yang, Li Nian, Shu Li, Li Yu Tng, Jun Zhuo Li, Shang Guan Ziyue, and Muhammad Sohaib Tahir
Advancements in electronic devices have led to increases in mental stress in modern adults, and removing this stress is crucial for mental health. The purpose of this study is to examine the psychophysiological benefits of contact with indoor plants. The effects of transplanting plants (horticultural activity) and work on a mobile phone (control activity) were assessed by blood pressure measurement, electroencephalography (EEG), the semantic differential method (SDM), and the State-Trait Anxiety Inventory (STAI). The SDM data showed that the subjects felt more relaxed, comfortable and natural, and experienced lower anxiety after the transplantation of plants than the control group. Participant’s total alpha and beta wave mean values increased over time during the transplantation task but decreased at the end of the control task. The mean meditation score was significantly higher after transplanting plants. Our study results indicate that contact with plants may minimize mental stress.
Tao Dong, Fang-cheng Bi, Yong-hong Huang, Wei-di He, Gui-ming Deng, Hui-jun Gao, Ou Sheng, Chun-yu Li, Qiao-song Yang, Gan-jun Yi, and Chun-hua Hu
An efficient biolistic transformation system of banana combined with a liquid medium selection system was developed during this study. An embryogenic cell suspension (ECS) of Musa acuminata cv. Baxi (AAA) was bombarded with a particle delivery system. After 7 days of restoring culture in liquid M2 medium, embryogenic cells were transferred to a liquid selection M2 medium supplemented with 10 μg/mL hygromycin for resistance screening. The untransformed cell clusters were inhibited or killed, and a small number of transformants proliferated in the liquid selection medium. After the 0th, first, second, and third generation of antibiotic screening, there were 0, 65, 212, and 320, respectively, vitality-resistant buds obtained from a 0.5-mL packed cell volume (PCV) of embryogenic cell suspension. The β-glucuronidase (GUS) staining, polymerase chain reaction (PCR) analysis, and Southern blot hybridization results all demonstrated a 100% positive rate of regenerated resistant seedlings. Interestingly, the number of buds obtained through third-generation screening was almost equal to that obtained from the original ECS in M2 medium without antibiotics. These results suggested that the liquid medium selection system facilitated the proliferation of a positive transgenic ECS, which significantly improved the regeneration rate of transformants. This protocol is suitable for the genetic transformation of all banana genotypes and is highly advantageous to varieties with low callusing potential.