Project description:Peroxidase (POD) activity was found to be positively correlated with insect resistance in maize kernels. Thus, we purified active PODs from (Zea mays, p84C3) kernels and subjected to LC-MS/MS analyses. To verify the identified putative plant PODs, we produced them by recombinant expression in E. coli. Whereas B4FFK9 did not display in vitro activity, B6T173 (ZmPrx35) was active and also exhibits a heme cofactor. B6T173 accounts for about 80% of the POD activity in the kernel, according to densitometric evaluation.
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.
Project description:Camptothecin (CPT) is a plant alkaloid that specifically binds topoisomerase I (Topo I) inhibiting its activity and inducing double stranded breaks in the DNA, activating the genotoxic cell responses, and ultimately, it might trigger programmed cell death (PCD). We used microarrays to detail the changes in gene expression during as a consequence of CPT treatment in maize immature embryos. In four independent experiments immature embryos were plated on MS medium supplemented with 50 uM CPT and incubated during three days. Untreated embryos incubated on MS medium were used as controls.
Project description:Transcriptional profiling of 4 maize varieties comparing genetic root response under control temperature conditions with genetic root response under low temperature conditions
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:The maize death acids, 10-oxo-11-phytoenoic acid and derivatives, are rapidly induced phytoalexins with multiple biological activities
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:Using the RL-SAGE method (Gowda et al. 2004), a maize leaf longSAGE library (cv. inbred line B73) was constructed. Leaf tissues were harvested from 4-week old B73 plants for RNA isolation. The conditions in the growth chamber were 12 h light (500 µmol photons m-2 sec-1), 20oC at night, 26oC in the day and 85% relative humidity. A total of 44,870 unique tags (17 bases +CATG) were identified from 232,948 individual tags in the maize leaf library.
Project description:Papain-like cysteine proteases (PLCPs) play important roles in plant defense mechanisms. Previous work identified a set of five apoplastic PLCPs (CP1A, CP1B, CP2, XCP2 and CatB) which are crucial for the orchestration of SA-dependent defense signaling and vice versa in maize (Zea mays). One central question from these findings is which mechanism is triggered by apoplastic PLCPs to induce SA-dependent defenses. By a mass spectrometry approach we discovered a novel peptide (Zip1 = Zea mays immune signaling peptide) to be enriched in apoplastic fluid upon SA treatment. Zip1 induces PR-gene expression when applied to naїve maize leaves. Moreover, it activates apoplastic PLCPs similar as SA does, suggesting Zip1 to play an important role in SA-mediated defense signaling. In vitro studies using recombinant protein showed that CP1A and CP2, but not XCP2 and CatB, release Zip1 from its pro-peptide (PROZIP1) in vitro. Strikingly, metabolite analysis showed direct induction of SA de novo synthesis by Zip1 in maize leaves. In line with this, RNA sequencing revealed that Zip1-mediated changes in maize gene expression largely resemble SA-induced responses. Consequently, Zip1 increases maize susceptibility to the necrotrophic fungal pathogen Botrytis cinerea. In summary, this study identifies the PLCP-released peptide signal Zip1, which triggers SA signaling in maize.