Project description:Subgroup Ib BHLH genes are induced by Fe deficiency. BHLH038 and BHLH039 were shown to be connected with salicylic acid. The triple knockout 3xbhlh (bhlh039-1 bhlh100-1 bhlh101-1) shows a stronger leaf chlorosis at - Fe than the wild type. The responses of this triple mutant were studied at - Fe in comparison to the wild type in the presence and absence of salicylic acid (SA).
Project description:Subgroup Ib BHLH genes are induced by Fe deficiency. BHLH038 and BHLH039 were shown to be connected with salicylic acid. The triple knockout 3xbhlh (bhlh039-1 bhlh100-1 bhlh101-1) shows a stronger leaf chlorosis at - Fe than the wild type. The responses of this triple mutant were studied at - Fe in comparison to the wild type in the presence and absence of salicylic acid (SA). Wild type and 3xbhlh seedlings (bhlh039-1 bhlh100-1 bhlh101-1) were grown at M-bM-^@M-^S Fe and treated for six hours with or without 100 M-BM-5M SA. Three biological replicates were generated.
Project description:AtR8 is a long non-coding RNA transcribed by RNA polymerase III in Arabidopsis which is responsive to hypoxic stress and salicylic acid. To understand the role of AtR8 lncRNA, microarray was carried out in the mutant seedlings of AtR8 and compared with wild type seedlings.
Project description:We found that amino acid transporter LHT1 was required for negatively regulating plant defence responses in addition to its physiological role in development and growth. In order to identify which defense pathways were involved in this process, we compared the expression profiles between wild type and lht1 mutant leaves without or with infection by Pseudomonas syringae pv. tomato DC3000 (Pst). In the lht1 mutant, except the changes in nitrogen metabolism-, cellular redox-, and photorespiration-associated gene expressions, the most drastic upregulations were found in the salicylic acid pathway-associated defense genes.
Project description:The sid2.2 mutant (Dewdney et al. 2000) with deletion/arrangement in exon 9 is deficient for salicylic acid synthesis. We used Affymetrix microarrays to detail the global programme of gene expression underlying metabolic and cellular changes in the rosettes of the Arabidopsis sid2.2 mutant and wild type grown under strong sulfate limitation.
Project description:Several phytohormones and other small molecules have been demonstrated to be involved in iron (Fe) homeostasis. However, how salicylic acid (SA), an essential hormone in plant immunity and defense responses, participates in Fe-deficiency responses in plants is largely unknown. Here, we took advantage of a SA biosynthesis defect mutant phytoalexin deficient 4 (pad4: T-DNA Salk_089936) to explore the possible effects of endogenous SA on the morphological and physiological responses to Fe deprivation. Under a Fe-deficiency treatment, Col-0 showed more severe leaf chlorosis and root growth inhibition compared with the pad4 mutant. The soluble Fe concentrations were significant higher in pad4 than Col-0 under the Fe-deficiency treatment, suggesting that a mutation in the PAD4 gene may alleviate the Fe-deficiency-induced symptoms by regulating the soluble Fe concentrations. Furthermore, a SA signaling maker line (PR1promoter: GUS) was used to investigate how Fe deficiency affects endogenous SA biosynthesis and metabolism. The data showed that Fe deficiency significantly induced SA accumulation in Col-0, and the loss function of PAD4 blocked this process. The requirement of endogenous SA accumulation for Fe-deficiency responses was confirmed using a series of SA biosynthetic mutants and transgenic lines.
Project description:The goal of the microarray was to investigate the transcriptome changes induced by exogenous NAD+ in the wild-type Col-0 plants. Results showed that exogenous NAD+-induced dramatic transcriptional changes in Arabidopsis. Particularly, a large group of salicylic acid pathway genes including NPR1 and its traget genes were induced by NAD+, whereas the jasmonic acid/ethylene pathway defense marker gene PDF1.2 was inhibited by NAD+ treatment. In addition, a group of the pathogen-associated molecular pattern pathway genes were also induced by exogenous NAD+. These results indicate that exogenous NAD+ induces defense pathways against (hemi)biotrophic pathogens but suppresses defense against necrotrophs.
