Search Results

You are looking at 1 - 10 of 21 items for

  • Author or Editor: Jing Li x
  • Refine by Access: User-accessible Content x
Clear All Modify Search
Free access

Jing-jing Zhao, Xun Chen, Li-juan Fan, and Ling Wang

Free access

Jing Ma, Zheng Li, Bin Wang, Shunzhao Sui, and Mingyang Li

Expansins are extracellular proteins that are involved in cell wall modifications such as cell wall disassembly, cell separation, and cell expansion. Little is known about expansin gene expression during flower development of wintersweet (Chimonanthus praecox). In the present study, an expansin gene, CpEXP1, was isolated from the wintersweet flower cDNA library through random sequencing; this gene encodes a putative protein of 257 amino acids with the essential features conserved, like in other alpha expansins. The CpEXP1 gene exhibited different transcription levels in different tissues and had a significantly higher expression in flowers than other tissues. It is strongly correlated with the development of the flower. The expression of CpEXP1 increased in the flower buds or whole flowers from Stage 1 to 4 and decreased from Stage 5 to 6 during natural opening. Ethephon (an ethylene releaser) treatment promoted cut flower senescence, whereas 1-methylcyclopropene (1-MCP) (an ethylene perception inhibitor) delayed the process of flower wilting. This result is associated with the concomitant lower transcript levels of CpEXP1 in the ethephon-treated samples as well as the steady expression in the 1-MCP-treated samples compared with that in control flowers. The studies show the interesting observation that the expression of an expansin gene CpEXP1 is correlated with the development of Chimonanthus praecox flowers, the upregulation during flower opening vs. the downregulation during senescence.

Open access

Qiuyue Ma, Shushun Li, Jing Wen, Lu Zhu, Kunyuan Yan, Qianzhong Li, Shuxian Li, and Bin Zhang

Acer truncatum seeds are an excellent source of beneficial natural compounds, including high levels of unsaturated fatty acids (UFAs), that promote health. Recently, A. truncatum has emerged as an oil crop. Therefore, the transcriptomes of A. truncatum seeds at 70, 85, 100, 115, 145, 180 days after flowering (DAF) were analyzed to gain a better understanding of the transcriptional and translational regulation of seed development and oil biosynthesis. A total of 28,438 genes were identified, and 3069/2636, 3288/3438, 1319/2750, and 5724/5815 upregulated/downregulated genes were identified when comparing different samples with 85 DAF seeds. Sixteen lipid metabolism pathways with 754 differentially expressed genes (DEGs) were identified, including 34 DEGs associated with UFA biosynthesis. A phylogenetic analysis revealed that six putative fatty acid desaturase (FAD) genes clustered into five FAD groups. A quantitative real-time polymerase chain reaction analysis indicated that the temporal expression patterns of oil biosynthesis genes and transcription factors were largely similar to the RNA sequencing results. The results of this study will enhance the current understanding of oil metabolism in A. truncatum seeds and allow new methods of improving oil quality and seed yield in the future.

Free access

Jing-fen Chen, Paul H. Li, and David W. Davis

Exposure of young pepper plants to chilling temperatures delays the development of terminal flower buds to flowering during post-stress growth. Degree of adverse influence depends on chilling intensity, exposure duration and varietal sensitivity. `Ma Belle' pepper plants were grown in a greenhouse (GH) during winter months on the St. Paul campus, No supplemental lighting was provided. When plants were at the 2- to 3-leaf stage, they were foliar sprayed with mefluidide (Technical grade) at 0, 5, 10 and 15 ppm. One day after treatment, some plants were transferred from GH to a cold room (3° ∼4°C day/night) with 12-h photoperiod. Treatad plants remaining in the GH served as the control. Plants were chilled for 1, 2, 4 and 6 days and then brought back to the GH for post-stress growth and development observation. Treated and untreated plants grown in the GH showed no difference in days to flowering, and reached 50% flowering at about 62 days after treatment. When untreated plants were chilled for 1,2,4 and 6 days, they showed a delay of 8, 18, 30 and 34 days, respectively, to flowering, If not killed, as compared to the control The long delay to flowering was due to the injury of the terminal flower buds. After 4 and 6 days of chilling, most terminal flower buds were killed. However, when plants were treated with mefluidide and subsequently chilled days to flowering were significantly shortened. A difference of 10-12 days was observed between chilled untreated plants and chilled treated plants. Concentrations of 5 to 15 ppm were equally effective in protection against chilling.

Free access

Jing-fen Chen, Paul H. Li, and David W. Davis

Exposure of young pepper plants to chilling temperatures delays the development of terminal flower buds to flowering during post-stress growth. Degree of adverse influence depends on chilling intensity, exposure duration and varietal sensitivity. `Ma Belle' pepper plants were grown in a greenhouse (GH) during winter months on the St. Paul campus, No supplemental lighting was provided. When plants were at the 2- to 3-leaf stage, they were foliar sprayed with mefluidide (Technical grade) at 0, 5, 10 and 15 ppm. One day after treatment, some plants were transferred from GH to a cold room (3° ∼4°C day/night) with 12-h photoperiod. Treatad plants remaining in the GH served as the control. Plants were chilled for 1, 2, 4 and 6 days and then brought back to the GH for post-stress growth and development observation. Treated and untreated plants grown in the GH showed no difference in days to flowering, and reached 50% flowering at about 62 days after treatment. When untreated plants were chilled for 1,2,4 and 6 days, they showed a delay of 8, 18, 30 and 34 days, respectively, to flowering, If not killed, as compared to the control The long delay to flowering was due to the injury of the terminal flower buds. After 4 and 6 days of chilling, most terminal flower buds were killed. However, when plants were treated with mefluidide and subsequently chilled days to flowering were significantly shortened. A difference of 10-12 days was observed between chilled untreated plants and chilled treated plants. Concentrations of 5 to 15 ppm were equally effective in protection against chilling.

Free access

Xiaogang Li, Ling Jin, Jing Ling, and Zhongchun Jiang

Foliar application of hormones and nutrients can improve fruit quality, but specific conditions for applying hormones and nutrients may vary among fruit species. The objective of this study was to determine the effects of 6-BA, potassium phosphate (monobasic), and calcium chloride on fruit weight, palatability, and storage quality of 8-year-old pear trees, cv. Hosui. Foliar applications of 1 mg·L-1 6-BA, 0.3% potassium phosphate, 0.3% calcium chloride, or 0.3% potassium phosphate + 0.3% calcium chloride were made at 20-day intervals from June until maturity. All foliar applications increased average fruit weight over the control (distilled water). 6-BA or the combination of potassium phosphate and calcium chloride increased fruit weight more than did potassium phosphate or calcium chloride alone. Fruit palatability, measured as the ratio of sugar content to acid content, was significantly lower in 6-BA, potassium phosphate, and calcium chloride treatments than in the control. All treatments increased vitamin C content over the control. Fruit storage quality in calcium chloride or calcium chloride + potassium phosphate treatments was superior to that in the control. Potassium phosphate alone and 6-BA treatments had no effects on fruit storage quality. We conclude that foliar applications of 0.3% potassium phosphate + 0.3% calcium chloride or 1 mg·L-1 6-BA can increase average fruit weight and improve fruit palatability.

Full access

Jing Zhou, PingPing Li, JiZhang Wang, and Weiguo Fu

Light and temperature are two crucial factors affecting plant growth. Light intensities vary considerably with season and weather conditions. Reasonable light regulation at different temperatures is a key issue in environmental regulation. In this study, we determined the effects of light intensity and temperature on crop growth and development. Furthermore, we determined an optimal light value and a suitable light range at different temperatures for producing the lettuce Lactuca sativa L. Artificial climate chamber experiments were conducted at five light intensities (100, 200, 350, 500, and 600 μmol·m−2·s−1), as well as at low (15 °C/10 °C), medium (23 °C/18 °C), and high (30 °C/25 °C) temperatures. In these experiments, we investigated the photosynthetic rate; chlorophyll fluorescence parameters; total N, P, and K uptake; and growth of lettuce plants. The results indicated that at a low temperature, the values of effective quantum yield of photosystem II photochemistry (ΦPSII), net photosynthetic rate (P n), stomatal conductance (g S), and transpiration rate (T r) —as well as those of N, K, and P uptake—were the highest at 350 μmol·m−2·s−1, followed by 500 μmol·m−2·s−1, which resulted in higher values for leaf number (LN), leaf area (LA), dry weight (DW), and fresh weight (FW). At the medium temperature, the values of ΦPSII, P n, g S, and T r, as well as those of N, K, and P uptake were higher at 350, 500, and 600 μmol·m−2·s−1 than at other light intensities, resulting in high values for LN, LA, DW, and FW of lettuce plants. The LN, LA, and FW of lettuce plants were the highest at 500 μmol·m−2·s−1, whereas DW was the highest at 600 μmol·m−2·s−1. At a high temperature, lettuce plants exhibited the highest values of F v/F m, ΦPSII, P n, g S , and T r, as well as those of N, K, and P uptake for the 500 μmol·m−2·s−1 treatment; whereas LN, LA, FW, and DW were the highest at 600 μmol·m−2·s−1. In addition, the values of F v/F m indicated that lettuce plants were under stress under the following combinations: 600 μmol·m−2·s−1 at the low temperature, 100 μmol·m−2·s−1 at the medium temperature, and 100–350 μmol·m−2·s−1 at the high temperature. Based on these results, an optimal regulation strategy for light intensity at different temperature environments was proposed for lettuce cultivars similar to L. sativa L. in some regions, such as the subtropical regions of China. Specifically, for low temperatures, light intensities of 350 to 500 μmol·m−2·s−1are recommended for production, and an intensity of 350 μmol·m−2·s−1 provides optimal supplementary light during early spring and winter in greenhouses. For medium temperatures, light intensities of 350 to 600 μmol·m−2·s−1 are recommended, and 500 μmol·m−2·s−1 is the optimal value during the middle of spring and autumn. For high temperatures, light intensities of 500 to 600 μmol·m−2·s−1are recommended, and 600 μmol·m−2·s−1 is the optimal value of light intensity during late spring and early autumn.

Open access

Lili Dong, Tongrui Liu, Di Gao, Jing Li, and Jie Qian

Petunia (Petunia ×hybrida) is an important ornamental plant, and its branch development has become a hot research topic. In this study, PhSDG8, an ortholog of SET domain group 8 (SDG8), was cloned from the petunia cultivar Mitchell Diploid. It had an open reading frame (ORF) of 5070 bp and encoded 1689 amino acids, with Suppressor variegation 3–9, Enhancer of zeste, Trithorax (SET), Zinc finger-cysteine and tryptophan conserved (Zf-CW), associated with SET (AWS) and Post SET domains. The predicted amino acid sequence of PhSDG8 was most closely related to Nicotiana sylvestris ASHH2 (NsASHH2). Expression analysis revealed that PhSDG8 expressed highest in the stems and lowest in the axil. Subcellular localization analysis showed that PhSDG8 was localized in the nucleus. Overexpression of PhSDG8 reduced the branch number of Arabidopsis thaliana sdg8-2. The silencing of PhSDG8 resulted in an increase in the number of branches of petunia and significant upregulation of PhUGT74E2. These results suggested that PhSDG8 may be a candidate gene for regulating the branching of petunia.

Free access

Na Liu, Baoli Zhou, Xin Zhao, Bo Lu, Yixiu Li, and Jing Hao

Verticillium wilt (caused by Verticillium dahliae), a soilborne disease, often causes significant reductions of yield in eggplant (Solanum melongena L.) production where crop rotation is limited. Rootstock replacement through grafting is considered an effective method to control this disease. This 2-year study investigated the eggplant yield, resistance to verticillium wilt, and allelochemicals in root exudates of eggplant grafted onto a tomato rootstock. Both disease incidence and disease severity on grafted eggplant were markedly lower than those of nongrafted eggplants. Fifteen days after V. dahliae inoculation, grafted eggplants did not exhibit any infection, whereas the disease incidence and disease severity index of the nongrafted eggplants were 68.3% and 37.8% in 2006 and 66.7% and 36.3% in 2007, respectively. Twenty-five days after inoculation, disease incidences on grafted eggplants were only 8.1% and 9.5% in 2006 and 2007, respectively, but those of the nongrafted eggplants increased to 100%. As a result, early yield, total yield, and average fruit weight were significantly increased by grafting when inoculated with V. dahliae in 2006 and 2007. Mycelium growth of V. dahliae was inhibited by the root exudates of grafted eggplants. In contrast, the root exudates of nongrafted eggplants enhanced the mycelium growth. The gas chromatography–mass spectrometry analysis revealed that the composition in the root exudates released by grafted eggplants differed not only from the nongrafted eggplants, but also from the tomato rootstock plants. Ten chemical classes were isolated and identified in root exudates of grafted eggplants. Carbazoles, amines, azulene, and fluorene were only detected in the grafted eggplants. The relative contents of ester compounds were the highest in the root exudates from the grafted eggplant followed by derivatives of benzene, whereas the relative contents of benzene derivatives were much higher than that of the ester compounds in the root exudates from the nongrafted eggplant and tomato rootstock.

Free access

Zhi-li Suo, Xiao-qing Zhao, Jing-yu Sun, and Wen-hai Sun

There exist large accumulations of natural genetic diversifications under the natural and artificial selections on the flower among the Chinese tree peony cultivars incited by ornamental and medicinal uses in the past over 1500 years in China. Paeonia suffruticosa `Xiao Ci Wei' is a unique Chinese tree peony cultivar possessing special bicolored petals with tubular tip structure (Paeoniaceae). This natural mutant is not only a unique ornamental, but also a valuable material for scientific researches in Evodevotics.