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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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A combinatorial TRM‐OFP module bilaterally fine‐tunes tomato fruit shape
Summary The mechanisms that regulate the vast diversity of plant organ shapes such as the fruit remain to be fully elucidated. TONNEAU1 Recruiting Motif proteins (TRMs) have been implicated in the control of organ shapes in a number of plant species, including tomato. However, the role of many of them is unknown. TRMs interact with Ovate Family Proteins (OFPs) via the M8 domain. However, thein plantafunction of the TRM‐OFP interaction in regulating shape is unknown.We used CRISPR/Cas9 to generate knockout mutants in TRM proteins from different subclades and in‐frame mutants within the M8 domain to investigate their roles in organ shape and interactions with OFPs.Our findings indicate that TRMs impact organ shape along both the mediolateral and proximo‐distal axes of growth. Mutations inSltrm3/4andSltrm5act additively to rescue the elongated fruit phenotype ofovate/Slofp20(o/s) to a round shape. Contrary, mutations inSltrm19andSltrm17/20aresult in fruit elongation and further enhance the obovoid phenotype in theo/smutant.This study supports a combinatorial role of the TRM‐OFP regulon where OFPs and TRMs expressed throughout development have both redundant and opposing roles in regulating organ shape.
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- Award ID(s):
- 2048425
- PAR ID:
- 10414366
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- New Phytologist
- Volume:
- 238
- Issue:
- 6
- ISSN:
- 0028-646X
- Format(s):
- Medium: X Size: p. 2393-2409
- Size(s):
- p. 2393-2409
- Sponsoring Org:
- National Science Foundation
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