Project description:In this study a transcriptomic approach (RNA-sequencing) was utilized to elucidate molecular responses of maize (Zea mays L.) primary roots of the inbred line B73 to water deficit to gain a better understanding of the mechanisms underlying drought tolerance. Kernels of the maize inbred line B73 were germinated in paper rolls soaked with distilled water until seedlings had a primary root length of 2 to 4 cm. For mild and severe water deficit conditions, seedlings were transferred to PEG8000 solution with water potentials of -0.2 MPa and -0.8 MPa, respectively. Water deficit treatment was applied for 6 h and 24 h. Each treatment was performed in four biological replicates each consisting of 10 roots.
Project description:Maize (Zea mays L.) was hydroponically grown for 14 days and then stressed with hypoxia. Maize roots were sampled after 24 hours and analyzed by mass spectrometry.
Project description:Plant nutrition takes advantage by the simultaneous presence of more N forms in the rhizosphere. In the last decades the interplay between ammonium and nitrate acquisition systems in roots has been deeply investigated. Although widely used as fertilizers, the occurrence of cross connection between urea and ammonium nutrition has been scarcely studied in plants, especially at molecular level. In a recent paper we provided evidence that maize plants fed with urea and ammonium mix showed a better N-uptake efficiency than plants fed with ammonium or urea alone. To elucidate the molecular mechanism underlying this response, transcriptomic and metabolomic changes occurring in maize plants were investigated. Transcriptomic analyses indicated that several transporters and enzymes involved in N-nutrition were found upregulated by all three N-treatments (AMT1.3, NRT1.1, NRT2.1, GS1, GOGAT, GDH), confirming that urea is a direct source of N for plants. Depending on N-form available in nutrient solution a peculiar response at transcriptomic and metabolomic level was observed, especially after 24 hours of treatment. In comparison to one single N-form, urea and ammonium mix induced a prompt assimilation of N, characterized by an overaccumulation of main amino acids in shoots, and an upregulation of ZmAMT1.1. Moreover even a peculiar modulation of aquaporins, carbonic anydrases, glutamine synthetase, amino aspartate, as well as the glycolysis-TCA cycle was induced in roots by urea and ammonium mix. Depending on N-form available in the external media, even changes in phytohormone’s composition were observed in maize (CKs, ABA, JA); in particular, already after 24 hours of treatment, urea induced the accumulation of trans-zeatin in shoots. Through a multiomics approach, we provide for the first time molecular characterization of maize response to urea and ammonium nutrition. This study paves the way to formulate guidelines for the optimization of N fertilization of crops to improve the N use efficiency in plants and therefore limit N losses in the environment.
Project description:In this study RNA-sequencing was used to monitor gene expression changes in four tissues (meristematic zone, elongation zone, and cortex and stele of the mature zone) of maize (Zea mays L.) primary roots in response to water deficit to gain a better understanding of the mechanisms underlying drought tolerance.
Project description:Intercropping is a vital technology in resource-limited agricultural systems with low inputs. Peanut/maize intercropping enhances iron (Fe) nutrition in calcareous soil. Proteomic studies of the differences in peanut leaves, maize leaves and maize roots between intercropping and monocropping systems indicated that peanut/maize intercropping not only improves Fe availability in the rhizosphere but also influences the levels of proteins related to carbon and nitrogen metabolism. Moreover, intercropping may enhance stress resistance in the peanut plant (Xiong et al. 2013b). Although the mechanism and molecular ecological significance of peanut/maize intercropping have been investigated, little is known about the genes and/or gene products in peanut and maize roots that mediate the benefits of intercropping. In the present study, we investigated the transcriptomes of maize roots grown in intercropping and monocropping systems by microarray analysis. The results enabled exploration differentially expressed genes in intercropped maize. Peanut (Arachis hypogaea L. cv. Luhua14) and maize (Zea mays L. cv. Nongda108) seeds were grown in calcareous sandy soil in a greenhouse. The soil was enhanced with basal fertilizers [composition (mg·kg−1 soil): N, 100 (Ca (NO3)2·4H2O); P, 150 (KH2PO4); K, 100 (KCl); Mg, 50 (MgSO4·7H2O); Cu, 5 (CuSO4·5H2O); and Zn, 5 (ZnSO4·7H2O)]. The experiment consisted of three cropping treatments: peanut monocropping, maize monocropping and intercropping of peanut and maize. After germination of peanut for 10 days, maize was sown. Maize samples were harvested after 63 days of growth of peanut plants based on the degree of Fe chlorosis in the leaves of monocropped peanut. The leaves of monocropped peanut plants exhibited symptoms of Fe-deficiency chlorosis at 63 days, while the leaves of peanut plants intercropped with maize maintained a green color.
Project description:Maize is one of the most important crops in the world. With the exponentially increasing population and the need for ever increased food and feed production, an increased yield of maize grain (as well as rice, wheat and other grains) will be critical. Maize grain development is understood from the perspective of morphology, hormone responses, and storage reserve accumulation. This includes various studies on gene expression during embryo development and maturation but a global study of gene expression of the embryo has not been possible until recently. Transcriptome analysis is a powerful new tool that can be used to understand the genetic basis of embryo maturation. We undertook a transcriptomic analysis of normal maturing embryos at 15, 21 and 27 days after pollination (DAP), of one elite maize germplasm line that was utilized in crosses to transgenic plants. More than 19,000 genes were analyzed by this method and the challenge was to select subsets of genes that are vitally important to embryo development and maturation for the initial analysis. We describe the changes in expression for genes relating to primary metabolic pathways, DNA synthesis, late embryogenesis proteins and embryo storage proteins, shown through transcriptome analysis and confirmed levels of transcription for some genes in the transcriptome using qRT-PCR.
Project description:Drought represents a major constraint on maize production worldwide. Understanding the genetic basis for natural variation in drought tolerance of maize may facilitate efforts to improve this trait in cultivated germplasm. Here, using a genome-wide association study, we show that a miniature inverted-repeat transposable element (MITE) inserted in the promoter of a NAC gene (ZmNAC111) is significantly associated with natural variation in maize drought tolerance. For maize RNA-seq analysis, pooled tissues from three, eight-day-old maize seedlings were collected from transgenic and wild-type plants, prior to or after 2-hour dehydration, to conduct the RNA-seq analysis.
Project description:It was investigated the changes in protein expression in maize roots in response to treatment with Herbaspirillum seropedicae. To identify maize proteins whose expression levels were altered in the presence of bacteria, a label-free quantitative proteomic approach was used.
Project description:Through hierarchical clustering of transcript abundance data across a diverse set of tissues and developmental stages in maize, we have identified a number of coexpression modules which describe the transcriptional circuits of maize development.