Horticulture, Environment, and Biotechnology

Asteraceae, the largest known plant family in the world, contains economically important species including ornamental plants. The most abundant enzyme on Earth, Ribulose-1,5-bisphosphate (RuBisCo), catalyzes the first step of carbon assimilation in photosynthesis. In this study, we conducted sequence, physicochemical, phylogenetic, and three-dimensional comparative analyses of 22 RuBisCo proteins in the Asteraceae using various bioinformatic tools. The alignment results showed that all residues corresponding to the region between 48-179 amino acids were conserved in all species, except for just seven residues: G79, I80, S88, F90, F93, I135, and S136. The sequence lengths of the RuBisCo large subunits were between 163 and 477 amino acids, with an average length of 255 amino acids. Their molecular weights (Mw) ranged from 18341.8 to 52895.1 Da, with an average Mw of 26294.5 Da. We found that the most abundant amino acid residue was Gly, which comprised 9.88% of these RuBisCo proteins. Ala (8.17%) and Leu (8.53%) were also both abundant. The extinction coefficient of the RuBisCo proteins at 280 nm ranged from 27515 to 69830 M-1 cm-1. The instability index values ranged from 24.41 to 40.65, and only one protein (from Gymnarrhena micrantha) was unstable in vitro. The aliphatic index values ranged from 72.56 to 81.13, while the GRAVY values ranged from -0.394 to -0.179. A total of ten motifs were identified in the sequences of the RuBisCo proteins. Phylogenetic analysis revealed that the 22 RuBisCo proteins formed two main clades. A RAMPAGE analysis revealed that 95.0-98.4% of residues were located in the favored region in 22 RuBisCo proteins. Sequence alignment and 3D analysis revealed that a catalytically important Lys residue was conserved among all the RuBisCo enzymes of Asteraceae. The results of this study provide insights into the fundamental characteristics of the RuBisCo proteins of the Asteraceae.

Due to increasing soil salinity, the world agricultural output is being threatened by the shrinking area of fertile land. In the present study, we explored the interactive roles of nitric oxide (NO; 100 μM) and spermidine (SP; 200 μM) in ameliorating the effects of salt stress (NaCl; 100 mM) in tomato (Solanum lycopersicum L. var. Five Star) seedlings. NaCl stress reduced shoot and root length, shoot and root fresh weight, shoot and root dry weight plant -1 and leaf area leaf -1. NaCl stress also suppressed the biosynthesis of photosynthetic pigments (Chlorophyll a and b) and increased proline (Pro) content, membrane damage and lipid peroxidation by inducing reactive oxygen species (H2O2 and O2• - ) generation in roots and leaves, as well as electrolyte leakage (EL) and malondialdehyde (MDA) accumulation in leaves. However, applying NO and/or SP increased the activities of catalase, peroxidase, superoxide dismutase, glutathione reductase and ascorbate peroxidase and increased photosynthetic pigment (chlorophyll a and b) and Pro accumulation, as well as reducing H2O2 and O2• - and MDA content and EL, under salt stress. When tomato plants were treated with NO and SP simultaneously, NO signaling was further enhanced, which was confirmed by the addition of cPTIO [2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide; NO scavenger].

Fresh-cut vegetables can cause food poisoning due to contamination with pathogenic bacteria. In this study, in order to examine the effect of a combined treatment using an organic acid and surfactant on the microbial populations over perilla leaves, samples were treated with 1% citric acid and various concentrations (0.05, 0.1, 0.2, and 0.3%) of Tween 20. It was observed that after the combined treatment of 1% citric acid and 0.1% Tween 20, the aerobic mesophilic bacteria populations on perilla leaves decreased by 2.61 log CFU/g compared to the control. In addition, Escherichia coli O157:H7 and Salmonella typhimurium inoculated on perilla leaves were not detected after the combined treatment of citric acid and Tween 20. These results suggest that treatment with citric acid and Tween 20 can be effective for the inactivation of microorganisms on perilla leaves.

In Lilium, a popular horticulture crop, the main objective of crossbreeding is introgression of desirable genes and features into new cultivars. Commercial Lilium cultivars were produced primarily through 2n-gametes or 2x-gametes as parental plants or backcrossing. The primary genetic difference in 2 methods, is the presence of genomic recombination. Especially, GISH (genomic in situ hybridization) among molecular cytogenetic analysis, is the relevant technique to detect genetic information; genome composition, chromosome behavior during meiosis and recombination of hybrids as using their parental DNA as a probe. Based on previous studies, in this research, 12 LA (L. longiflorum x L. Asiatic hybrids) hybrids were analyzed by GISH (genomic in situ hybridization) along with ploidy analysis, and pollen germination tests. The LA hybrids used in this study, showed less pollen germination ability (ranged 0 - 21.74%), but germination of ‘Caesars Palace’ was significantly higher (59.09%). Interestingly, ploidy analysis showed that ‘Caesars Palace’ was tetraploid and ‘Batistero’ had one more additional chromosome from the L genome. Nine of the 12 cultivars exhibited recombination and 3 had only non-recombinant chromosomes; fewer L. longiflorum chromosomes were present in the cultivars than Asiatic chromosomes. Consequentially, it is assumed that 2n-gametes were more common methodology than 2x-gametes for producing commercial cultivars. Moreover, backcrossing tended to be performed with the Asiatic hybrid cultivar.

Transcription of defense genes in grapevines function by combining the transcription factors to overcome stresses caused by unfavorable environmental conditions. Heat shock transcriptional factors (HSFs) have the most important role in transcription of genes that respond to high temperatures. The present study identifies the structure and motif location of 19 grape HSF genes in Vitis flexuosa, and investigates their expression patterns in grapevines exposed to high temperatures. Examination of the V. flexuosa transcript database identified 19 VfHSFs, which include VHSFA, VHSFB, and VHSFC. Analysis of the amino acid sequences of VHSF genes revealed 10 motifs. Vines of ‘Campbell Early’, ‘Kyoho’ grapes, and V. flexuosa were exposed to 25 °C, 30 °C, 35 °C, 40 °C and 45 °C in incubation chambers, for varying time points (0, 3, 6, 12 and 24 h). Homologous genes (VfHSFs) of V. flexuosa were predicted by searching the HSF genes in the V. flexuosa transcripts database. Prediction of the protein structure demonstrated that all 19 VfHSF genes of V. flexuosa had an HSF domain. In order to validate the difference in gene expression among cultivars, the relative expression levels were measured using real-time PCR. We found 10 HSF genes (HSF2, HSF3, HSF4, HSF5, HSF7, HSF10, HSF14, HSF16, HSF17, and HSF18) showed differential expression patterns in response to high temperature in ‘Campbell Early’, ‘Kyoho’, and V. flexuosa grapevines. We consider that these results can be useful information to select genetic resources for the future development of heat tolerant grapes, and to study the reaction of grapevines to high temperatures.

The production of reactive oxygen species (ROS) in plants under low temperature stress causes damage to plants. In order to evaluate the antioxidant responses of Thomson navel young trees (two years old) on different rootstocks under low temperatures, an experiment was conducted in a factorial plan based on completely randomized design. Treatments of temperatures were at seven levels including 9, 6, 3, 0, −3, −6°C, and 25 ± 2°C (as control) and rootstocks were Sour orange, Citrange and Trifoliate orange. Results of interactive effects of factors showed that electrolyte leakage (EL), antioxidant capacity, catalase (CAT) and ascorbate peroxidase (APX) activity were significant at P < 0.01. Maximum EL was observed in Thomson navel on Sour orange at −6°C, while the highest antioxidant capacity, CAT and APX activity respectively with mean 75.06%, 0.45 and 4.350 IU·g−1 FW were observed in Thomson navel on Trifoliate orange rootstock at 0, −3 and 0°C. Low temperatures increased EL, lipid peroxidation, antioxidant capacity, superoxide dismutase (SOD), APX, CAT and peroxidase enzyme activities (P < 0.01). Due to effects of rootstock, lipid peroxidation reduced to 52 % (P < 0.01). The biochemical and physiological study of this experiment indicated that Thomson navel on Trifoliate orange rootstock, had best tolerance to freezing stress.

This study was conducted to investigate the growth and quality of three mint cultivars. Eau de cologne mint showed the best growth in terms of plant height, number of leaves, and fresh weight. Among quality traits, the chlorophyll content was highest in eau de cologne mint, whereas the vitamin C content was highest in pineapple mint. The nitrate, phosphate, and essential oil contents were higher in eau de cologne mint but the contents of the major essential oil constituents, L-limonene and L-menthone, were higher in apple and pineapple mint. The total yields of all three cultivars gradually increased with increasing harvesting period. The essential oil contents of eau de cologne and pineapple mint increased with increasing harvesting period, but that of apple mint decreased. The menthol contents of essential oil increased in apple and pineapple mint at each harvesting period, and 135 days after transplanting, major changes in oil constituents were detected in apple mint. Eau de cologne mint exhibited the best growth, whereas apple mint, with only slightly poorer growth, had better essential oil constituents.

Chúng tôi đã điều tra các điều kiện dẫn đến việc tích lũy saponin trong cây bằng cách sử dụng các nền văn hóa in vitro của Eryngium planum L. Mục tiêu là thiết lập một hệ thống sản xuất saponin có chất lượng tương đương với những gì có trong cây trồng ngoài đồng và tăng cường sự tích lũy của chúng trong phòng thí nghiệm. Chúng tôi nhận thấy rằng hàm lượng saponin trong các cơ quan từ các cây con in vitro và cây trồng trong các thí nghiệm sau khi nhân giống vi mô cao hơn (lên đến 8.7 lần) so với cây từ các khu vực tự nhiên. Callus không xử lý đã tích lũy saponin với lượng tương tự như rễ của cây trồng ngoài đồng. Việc áp dụng sucrose vào môi trường sinh trưởng với nồng độ cao hơn (40, 50 hoặc 60 g L−1) đã dẫn đến việc tăng cường sản xuất saponin trong callus (từ 1.2 đến 1.7 lần). Sự kích thích với 100 µmol L−1 methyl jasmonate của callus được trồng trên môi trường Murashige và Skoog bổ sung 30 g L−1 sucrose đã dẫn đến việc tích lũy saponin tăng 1.2 lần so với callus duy trì trên cùng một môi trường (30 g L−1 sucrose). Nghiên cứu này cung cấp bằng chứng đầu tiên rằng saponin triterpenoid có thể được tổng hợp sinh học trong các cây con in vitro và các nền văn hóa phân hóa lại của E. planum.