Project description:By comparing data from the three cytolines (two cytoplsm donors and one nucleus donor) we identified key nuclear genes whose expression is modulated through the retrograde signaling pathways.
Project description:Arabidopsis thaliana plants that have experienced an initial exposure to dehydration stress (“trained plants”) have an increased ability to maintain leaf relative water content (RWC) during subsequent stresses than plants experiencing the stress for the first time and transcription of selected dehydration response genes is altered during successive exposures to dehydration stress. This physiological and transcriptional behavior of trained plants is consistent with a “memory “of an earlier stress. It is unknown whether such memory is present in other Angiosperm lineages and whether it is an evolutionarily conserved response to stress. Here, we analyzed the behavior and transcriptomes of maize (Zea mays) plants experiencing multiple dehydration stresses and compare them with responses of the evolutionarily distant A. thaliana. We found structurally related genes in maize that displayed the same memory-type responses as in A. thaliana, providing evidence of the conservation of function and transcriptional memory in the evolution of plants’ dehydration stress response systems. Similar to A. thaliana, trained Z. mays plants retained higher RWC during dehydration stress than untrained plants, due in part to maintaining reduced stomatal conductance, despite full recovery of RWC, after the first stress. Divergent transcriptional memory responses were also expressed, suggesting diversification of function among stress memory genes. Some dehydration stress memory genes were also shared with other stress and hormone responding pathways, indicating complex and dynamic interactions between different plant signaling networks. The results provide new insight into how plants respond to multiple dehydration stresses and provide a platform for studies of the functions of memory genes in adaptive responses to water deficit in monocot and eudicot plants .
Project description:Using maize cytolines (same nucleus but different cytoplasms), our research adds a new facet to the paradigm explaining gene expression changes in response to heat stress in an effort to maintain the homeostasis, linking the response to the genetic divergence of the nuclear and organellar genomes.
Project description:Arabidopsis thaliana plants that have experienced an initial exposure to dehydration stress (“trained plants”) have an increased ability to maintain leaf relative water content (RWC) during subsequent stresses than plants experiencing the stress for the first time and transcription of selected dehydration response genes is altered during successive exposures to dehydration stress. This physiological and transcriptional behavior of trained plants is consistent with a “memory “of an earlier stress. It is unknown whether such memory is present in other Angiosperm lineages and whether it is an evolutionarily conserved response to stress (see E-GEOD-48235). Here, we analyzed the behavior and transcriptomes of maize (Zea mays) plants experiencing multiple dehydration stresses and compare them with responses of the evolutionarily distant A. thaliana. We found structurally related genes in maize that displayed the same memory-type responses as in A. thaliana, providing evidence of the conservation of function and transcriptional memory in the evolution of plants’ dehydration stress response systems. Similar to A. thaliana, trained Z. mays plants retained higher RWC during dehydration stress than untrained plants, due in part to maintaining reduced stomatal conductance, despite full recovery of RWC, after the first stress. Divergent transcriptional memory responses were also expressed, suggesting diversification of function among stress memory genes. Some dehydration stress memory genes were also shared with other stress and hormone responding pathways, indicating complex and dynamic interactions between different plant signaling networks. The results provide new insight into how plants respond to multiple dehydration stresses and provide a platform for studies of the functions of memory genes in adaptive responses to water deficit in monocot and eudicot plants . For each condition (water, S1, and S3) the transcriptome was sequenced for two replicates. The watered condition is considered the control.
Project description:Investigation of whole genome gene expression level changes in maize plants (standard maize line B73) in controlled conditions under continuous light. Tissues of the leaf elongation zone were sampled from plants well watered every 12 hours before and after lights on.
Project description:Analysis of transcriptome response of norflurazon treated or untreated 5-day old whole seedlings with genotypes: Col6-3 (wild type), gun1-9 and MORF2 overexpression lines. GUN1 and MORF2 are involved in chloroplast-to-nucleus retrograde signaling. Results provide insight into the nuclear genes expression profile under control of GUN1 retrograde pathways and the regulation similarity between gun1-9 and MORF2 overexpression lines.
Project description:Retrograde signals emanate from the DNA-containing cell organelles (plastids and mitochondria) and control the expression of a large number of nuclear genes in response to environmental and developmental cues. GENOMES UNCOUPLED1 (GUN1) participating in multiple retrograde signaling pathways that collectively regulate the nuclear transcriptome. We used microarrays to further investigate the regulation of nuclear gene expression by PGE retrograde signals mediated by GUN1.
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: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.