Project description:Plants perceive herbivory induced volatiles and respond to them by upregulating their defenses. So far, the organs responsible for volatile perception remain poorly described. Here, we show that responsiveness to the herbivory induced green leaf volatile (Z)-3-hexenyl acetate (HAC) in terms of volatile emission, transcriptional regulation and jasmonate defense hormone activation is largely constrained to younger maize leaves. Older leaves are much less sensitive to HAC. In a given leaf, responsiveness to HAC is high at immature developmental stages and drops off rapidly during maturation. Responsiveness to the non-volatile elicitor ZmPep3 shows an opposite pattern, demonstrating that this form of hyposmia (i.e. decreased sense of smell) is not due to a general defect in jasmonate defense signaling in mature leaves. Neither stomatal conductance nor leaf cuticle composition explain the unresponsiveness of older leaves to HAC, suggesting perception mechanisms upstream of jasmonate signaling as driving factors. Finally, we show that hyposmia in older leaves is not restricted to HAC, and extends to the full blend of herbivory induced volatiles. In conclusion, our work identifies immature maize leaves as dominant stress volatile sensing organs. The tight spatiotemporal control of volatile perception may facilitate within-plant defense signaling to protect young leaves, and may allow plants with complex architectures to explore the dynamic odor landscapes at the outer periphery of their shoots
Project description:This study evaluated the variability of methylxanthine content of Ilex guayusa under different geographical, light, and age conditions, as an opportunity to emphasize the value of the chakra agroforestry system in the search for sustainable use of natural products with potential industrial applications.
Project description:Maize (Zea mays L.) is one of the major cereal crops worldwide. Increasing planting density is an effective way to improve crop yield. However, plants grown under high-density conditions compete for water, nutrients, and light, which often leads to changes in productivity. To date, few studies have determined the transcriptomic differences in maize leaves in response to different planting densities. This study examined the whole-genome expression patterns in the leaves of maize planted under high and low densities to identify density-regulated genes. Leaves at upper, ear, and lower stem nodes were collected at the grain-filling stage of the maize hybrid Xianyu335 grown under low-density planting and high-density planting. In total, 72, 733, and 1,739 differentially expressed genes (DEGs) were identified in the respective upper, ear, and lower leaves under HDP. Upregulated and downregulated DEGs in the upper and lower leaves were similar in number, whereas upregulated DEGs in the ear leaves were significantly higher in number than the downregulated DEGs. Functional analysis indicated that genes responding to HDP-related stresses were mediated by pathways involving four phytohormones responsible for metabolism and signaling, osmoprotectant biosynthesis, transcription factors, and fatty acid biosynthesis and protein kinases, which suggested that these pathways are affected by the adaptive responses mechanisms underlying the physiological and biochemical responses of the leaves of maize planted at high density.
Project description:Cotton seeds (Gossypium hirsutum cv. CCRI12) were grown in a growth chamber under 29/25°C temperature and a 16:8 h light:dark cycle, and water was added every two days. All plants were used in experiments at the 6-7 fully expanded true leaf stage, which occurred 5-6 weeks after sowing. Cotton bollworm (CBW; Helicoverpa armigera) larvae were reared on an artificial diet and maintained at 27 ± 2°C, 75 ± 10% relative humidity, and 14:10 h light:dark in the laboratory. For insect treatment, seven H. armigera larvae (third instars) were placed on a group of three plants, which were kept within plastic bags (30 × 40 cm), until time of harvest, with samples for each time point maintained separately. Undamaged plants maintained under the same conditions were used as controls. Cotton leaves from control plants and plants exposed to H. armigera were harvested at 6 h, 12 h, 24 h, and 48 h after onset of herbivory. For each treatment group and time point, cotton leaves were harvested from the three plants per treatment group and flash frozen in liquid nitrogen. For each time point, three replicate treatments and controls were performed. For insect treatment, seven H. armigera larvae (third instars) were placed on a group of three plants, which were kept within plastic bags (30 × 40 cm), until time of harvest, with samples for each time point maintained separately. Undamaged plants maintained under the same conditions were used as controls. Cotton leaves from control plants and plants exposed to H. armigera were harvested at 6 h, 12 h, 24 h, and 48 h after onset of herbivory. For each treatment group and time point, cotton leaves were harvested from the three plants per treatment group and flash frozen in liquid nitrogen. For each time point, three replicate treatments and controls were performed.
Project description:Arabidopsis thaliana ecotypes Columbia (Col-0) (wild type: WT) was used in this study. After sterilization, the seeds were placed on Murashige and Skoog medium supplemented with 2% (w/v) sucrose for 10 days and then the seedling were transferred to soil under 16 hours light (22°C) / 8 hours dark (18°C) period in growth chamber at a light intensity of 120?150 µmol m-2 s-1. 20-day-old Arabidopsis leaves without bolting were immediately frozen in liquid nitrogen for RNA and protein and metabolites extraction. Leaves were harvested at three different time points: t = 0 hr (end of night), t = 1 hr (one hour after light turn on) and t = 8 hr (eight hours after light turn on), respectively.
Project description:This study evaluated the variability of methylxanthine content of Ilex guayusa under different geographical, light, and age conditions, as an opportunity to emphasize the value of the chakra agroforestry system in the search for sustainable use of natural products with potential industrial applications.
Project description:RNAseq transcriptome of leaves and roots of Arabidopsis thaliana Columbia-0 grown under control (ES media) and Fe-deficiency (-Fe +100 µM FRZ) conditions.