title: Nitric Oxide Responsive Heavy Metal-Associated GeneAtHMAD1Contributes to Development and Disease Resistance inArabidopsis thaliana.
abstract: Exposure of plants to different biotic and abiotic stress condition instigates significant change in the cellular redox status; resulting in the elevation of reactive nitrogen species that play signaling role in mediating defense responses. Heavy metal associated (HMA) domain containing genes are required for spatio-temporal transportation of metal ions that bind with various enzymes and co-factors within the cell. To uncover the underlying mechanisms mediated byAtHMAgenes, we identified 14Arabidopsis HMAgenes that were differentially expressed in response to nitrosative stress through RNA-seq analysis. Of those 14 genes, the expression of eight HMA genes was significantly increased, whereas that of six genes was significantly reduced. We further validated the RNA-seq results through quantitative real-time PCR analysis. Gene ontology analysis revealed the involvement of these genes in biological processes such as hemostasis and transport. The majority of these nitric oxide (NO)-responsiveAtHMAgene products are carrier/transport proteins.AtHMAD1(At1g51090) showed the highest fold change toS-nitrosocystein. We therefore, further investigated its role in oxidative and nitrosative mediated stress conditions and found that AtHMAD1 has antagonistic role in shoot and root growth. Characterization ofAtHMAD1through functional genomics showed that the knock out mutantathmad1plants were resistant to virulentPseudomonas syringae(DC3000) and showed early induction and high transcript accumulation of pathogenesis related gene. Furthermore, inoculation ofathamd1withavirulentstrain of the same bacteria showed negative regulation ofR-gene mediated resistance. These results were supported by hypersensitive cell death response and cell death induced electrolyte leakage. AtHMAD1 was also observed to negatively regulate systemic acquired resistance SAR as the KO mutant showed induction of SAR marker genes. Overall, these results imply that NO-responsiveAtHMAdomain containing genes may play an important role in plant development and immunity.
authors.affiliation: Laboratory of Plant Functional Genomics, School of Applied Biosciences, Kyungpook National University Daegu, South Korea.
authors.forename: Q Muhammad
authors.initials: QM
authors.lastname: Imran
authors.affiliation: Laboratory of Plant Functional Genomics, School of Applied Biosciences, Kyungpook National University Daegu, South Korea.
authors.forename: Noreen
authors.initials: N
authors.lastname: Falak
authors.affiliation: Department of Agriculture, Abdul Wali Khan University Mardan, Pakistan.
authors.forename: Adil
authors.initials: A
authors.lastname: Hussain
authors.affiliation: Laboratory of Plant Functional Genomics, School of Applied Biosciences, Kyungpook National University Daegu, South Korea.
authors.forename: Bong-Gyu
authors.initials: BG
authors.lastname: Mun
authors.affiliation: Laboratory of Plant Functional Genomics, School of Applied Biosciences, Kyungpook National University Daegu, South Korea.
authors.forename: Arti
authors.initials: A
authors.lastname: Sharma
authors.affiliation: Laboratory of Plant Functional Genomics, School of Applied Biosciences, Kyungpook National University Daegu, South Korea.
authors.forename: Sang-Uk
authors.initials: SU
authors.lastname: Lee
authors.affiliation: Laboratory of Plant Molecular Breeding, School of Applied Biosciences, Kyungpook National University Daegu, South Korea.
authors.forename: Kyung-Min
authors.initials: KM
authors.lastname: Kim
authors.affiliation: Laboratory of Plant Functional Genomics, School of Applied Biosciences, Kyungpook National University Daegu, South Korea.
authors.forename: Byung-Wook
authors.initials: BW
authors.lastname: Yun
keywords: HR response; R-gene mediated resistance; RNA-seq profile; basal defense; nitrosative stress