Project description:Previous studies have shown that methane (CH4) has promoting roles in the adventitious root (AR) and lateral root formation in plants. However, whether CH4 could trigger the bulblet formation in scale cutting of Lilium davidii var. unicolor has not been elucidated. To gain insight into the effect of CH4 on the bulblet formation, different concentrations (1%, 10%,50% and 100%) of methane-rich water (MRW) and distilled water were applied to treat the scale cuttings of Lilium. We observed that treatment with 100% MRW obviously induced the bulblet formation in scale cuttings. To explore the mechanism of CH4-induced the bulblet formation, the transcriptome of scales was analyzed. A total of 2078 differentially expressed genes (DEGs) were identified. The DEGs were classified into different metabolism pathways, especially phenylpropanoid biosynthesis, starch and sucrose metabolism and plant signal transduction. Of these, approximately 38 candidate DEGs involved in the plant signal transduction were further studied. In addition, the expression of AP2-ERF/ERF, WRKY, GRAS, ARF and NAC transcription factors were changed by MRW treatment, suggesting their potential involvement in bulblet formation. As for hormones, exogenous IAA, GA and ABA could indue the bulblet formation. Additional experiments suggested that MRW could increase the endogenous IAA, GA, and JA levels, but decrease the levels of ABA during bulblet formation, which showed that higher IAA, GA, JA levels and lower ABA content might facilitate bulblet formation. In addition, the levels of endogenous hormone were consistent with the expression level of genes involved in phytohormone signal transduction. Overall, this study has revealed that CH4 might improve the bulblet formation of cutting scales in Lilium by regulating the expression of genes related to phytohormone signal transduction and transcription factors, as well as by changing the endogenous hormone levels.
Project description:Lateral root initiation was used as a model system to study the mechanisms behind auxin-induced cell division. Genome-wide transcriptional changes were monitored during the early steps of lateral root initiation. Inclusion of the dominant auxin signaling mutant solitary root1 (slr1) identified genes involved in lateral root initiation that act downstream of the AUX/IAA signaling pathway. Interestingly, key components of the cell cycle machinery were strongly defective in slr1, suggesting a direct link between AUX/IAA signaling and core cell cycle regulation. However, induction of the cell cycle in the mutant background by overexpression of the D-type cyclin (CYCD3;1) was able to trigger complete rounds of cell division in the pericycle that did not result in lateral root formation. Therefore, lateral root initiation can only take place when cell cycle activation is accompanied by cell fate respecification of pericycle cells. The microarray data also yielded evidence for the existence of both negative and positive feedback mechanisms that regulate auxin homeostasis and signal transduction in the pericycle, thereby fine-tuning the process of lateral root initiation. Experiment Overall Design: Seedlings of both wild type (Col-0) and the lateral root defective mutant (slr-1) were germinated on MS medium supplemented with 10μM NPA (=auxin transport inhibitor). Three days after germination, such seedlings were transferred to MS supplemented with 10μM NAA for 0h, 2h and 6h respectively. The segment between root meristem and root-hypocotyl junction was harvested from about 1500 seedling per time point. All treatments were repeated biologically. 5.8 μg total RNA was used for the preparation of biotinylated cRNA. Labeled RNA was hybridised to ATH1 Affymetrix chips. The resulting data was MAS5.0 normalised.
Project description:To obtain the global gene expression of Eucommia ulmoides, microarray analyses based on EST was conducted. We used 5 kinds of samples (inner stem, outer stem, immature fruit, flower, and leaf) with hormon (IAA, NPA, ABA), light (dark, bright field) & temperature (27, 37, 42°C) treatmens. In total, 102 independent samples were analysed.
Project description:We developed a method to synchronize the induction of lateral roots in primary and adventitious roots of Zea mays, and used it to perform a genome-wide transcriptome analysis of the pericycle cells in front of the phloem poles during lateral root initiation. Lateral roots were induced in primary and adventitious roots of Maize. For the primary root, plants were germinated and grown 64 hours in NPA 50 µM, and then transfered to NAA 50 µM. For the adventitious roots, plants were germinated and grown in water for 6 days, then tranfered 4 days in NPA 25 µM, and finally transfered to NAA 25 µM. For all these roots, pericycle cells located in front of the phloem poles in segments of roots located between 5 and 10 mm distance from the root tip were isolated using laser capture microdissection after cryosection. Material was sampled at 0 hours (NPA) and after 2, 3 and 4 hours of NAA treatment, for both the primary and adventitious roots and also after 6 hours and 9 hours of NAA treatment for the adventitious roots.