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Summary All aerial epidermal cells in land plants are covered by the cuticle, an extracellular hydrophobic layer that provides protection against abiotic and biotic stresses and prevents organ fusion during development.Genetic and morphological analysis of the classic maizeadherent1(ad1) mutant was combined with genome‐wide binding analysis of the maize MYB transcription factor FUSED LEAVES1 (FDL1), coupled with transcriptional profiling offdl1mutants.We show thatAD1encodes an epidermally‐expressed 3‐KETOACYL‐CoA SYNTHASE (KCS) belonging to a functionally uncharacterized clade of KCS enzymes involved in cuticular wax biosynthesis. Wax analysis inad1mutants indicates thatAD1functions in the formation of very‐long‐chain wax components. We demonstrate that FDL1 directly binds to CCAACC core motifs present inAD1regulatory regions to activate its expression. Over 2000 additional target genes of FDL1, including many involved in cuticle formation, drought response and cell wall organization, were also identified.Our results identify a regulatory module of cuticle biosynthesis in maize that is conserved across monocots and eudicots, and highlight previously undescribed factors in lipid metabolism, transport and signaling that coordinate organ development and cuticle formation.
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Improved pathogen and stress tolerance in tomato mutants of SET domain histone 3 lysine methyltransferases
Summary Histone lysine methylations (HLMs) are implicated in control of gene expression in different eukaryotes. However, the role of HLMs in regulating desirable crop traits and the enzymes involved in these modifications are poorly understood.We studied the functions of tomato histone H3 lysine methyltransferases SET Domain Group 33 (SDG33) and SDG34 in biotic and abiotic stress responses.SDG33andSDG34gene edited mutants were altered in H3K36 and H3K4 methylations, and expression of genes involved in diverse processes and responses to biotic and abiotic stimuli.The double but not the single mutants show resistance to the fungal pathogenBotrytis cinerea.Interestingly, single mutants were tolerant to drought and the double mutant showed superior tolerance and plant growth consistent with independent and additive functions. Mutants maintained higher water status during drought and improved recovery and survival after lapse of drought.Notably, diminution of H3K4 and H3K36 trimethylation and expression of negative regulators in challenged plants contributes to stress tolerance of the mutants. Mutations inSDG33andSDG34are likely to remove predisposition to biotic and abiotic stress by disrupting permissive transcriptional context promoting expression of negative regulatory factors. These allows improvement of stress and pathogen tolerance, without growth trade‐offs, through modification of histone epigenetic marks.
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- Award ID(s):
- 1916893
- PAR ID:
- 10445327
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- New Phytologist
- Volume:
- 235
- Issue:
- 5
- ISSN:
- 0028-646X
- Page Range / eLocation ID:
- p. 1957-1976
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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