Plant lateral organ development is a complex process involving both transcriptional activation and repression mechanisms. The We developed a novel Mt Our findings together suggest that transcriptional repression and activation mediated by the
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, the 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 in 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.
- Award ID(s):
- 2048425
- NSF-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
More Like this
-
more » « less
Summary WOX transcriptional repressorWOX 1/STF , theLEUNIG (LUG ) transcriptional corepressor and theANGUSTIFOLIA 3 (AN 3) transcriptional coactivator play important roles in leaf blade outgrowth and flower development, but how these factors coordinate their activities remains unclear. Here we report physical and genetic interactions among these key regulators of leaf and flower development.in planta transcriptional activation/repression assay and suggest thatLUG could function as a transcriptional coactivator during leaf blade development.LUG physically interacts with MtAN 3, and this interaction appears to be required for leaf and flower development. A single amino acid substitution at position 61 in theSNH domain of MtAN 3 protein abolishes its interaction with MtLUG , and its transactivation activity and biological function. Mutations inlug andan3 enhanced each other's mutant phenotypes. Both thelug and thean3 mutations enhanced thewox1 prs leaf and flower phenotypes inArabidopsis .WOX ,LUG andAN 3 regulators function in concert to promote leaf and flower development, providing novel mechanistic insights into the complex regulation of plant lateral organ development. -
more » « less
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.
SDG33 andSDG34 gene 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 pathogen
Botrytis 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 in
SDG33 andSDG34 are 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. -
more » « less
Summary Mitochondria play critical roles in generating ATP through oxidative phosphorylation (OXPHOS) and produce both damaging and signaling reactive oxygen species (ROS). They have reduced genomes that encode essential subunits of the OXPHOS machinery. Mitochondrial Transcription tERmination Factor‐related (mTERF) proteins are involved in organelle gene expression, interacting with organellar DNA or RNA.
We previously found that mutations in
Arabidopsis thaliana mTERF18/SHOT1 enable plants to better tolerate heat and oxidative stresses, presumably due to low ROS production and reduced oxidative damage.Here we discover that
shot1 mutants have greatly reduced OXPHOS complexes I and IV and reveal that suppressor ofhot1‐4 1 (SHOT1) binds DNA and localizes to mitochondrial nucleoids, which are disrupted inshot1 . Furthermore, three homologues of animal ATPase family AAA domain‐containing protein 3 (ATAD3), which is involved in mitochondrial nucleoid organization, were identified as SHOT1‐interacting proteins. Importantly, disrupting ATAD3 function disrupts nucleoids, reduces accumulation of complex I, and enhances heat tolerance, as is seen inshot1 mutants.Our data link nucleoid organization to OXPHOS biogenesis and suggest that the common defects in
shot1 mutants and ATAD3‐disrupted plants lead to critical changes in mitochondrial metabolism and signaling that result in plant heat tolerance. -
more » « less
Summary A network of peptidases governs proteostasis in plant chloroplasts and mitochondria. This study reveals strong genetic and functional interactions in Arabidopsis between the chloroplast stromal CLP chaperone‐protease system and the PREP1,2 peptidases, which are dually localized to chloroplast stroma and the mitochondrial matrix.
Higher order mutants defective in CLP or PREP proteins were generated and analyzed by quantitative proteomics and N‐terminal proteomics (terminal amine isotopic labeling of substrates (TAILS)).
Strong synergistic interactions were observed between the CLP protease system (
clpr1‐2 ,clpr2‐1 ,clpc1‐1 ,clpt1 ,clpt2) and both PREP homologs (prep1 ,prep2 ) resulting in embryo lethality or growth and developmental phenotypes. Synergistic interactions were observed even when only one of the PREP proteins was lacking, suggesting that PREP1 and PREP2 have divergent substrates. Proteome phenotypes were driven by the loss of CLP protease capacity, with little impact from the PREP peptidases. Chloroplast N‐terminal proteomess howed that many nuclear encoded chloroplast proteins have alternatively processed N‐termini inprep1prep2 ,clpt1clpt2 andprep1prep2clpt1clpt2 .Loss of chloroplast protease capacity interferes with stromal processing peptidase (SPP) activity due to folding stress and low levels of accumulated cleaved cTP fragments. PREP1,2 proteolysis of cleaved cTPs is complemented by unknown proteases. A model for CLP and PREP activity within a hierarchical chloroplast proteolysis network is proposed.
-
more » « less
Societal Impact Statement Citrus are intrinsically connected to human health and culture, preventing human diseases like scurvy and inspiring sacred rituals. Citrus fruits come in a stunning number of different sizes and shapes, ranging from small clementines to oversized pummelos, and fruits display a vast diversity of flavors and aromas. These qualities are key in both traditional and modern medicine and in the production of cleaning and perfume products. By quantifying and modeling overall fruit shape and oil gland distribution, we can gain further insight into citrus development and the impacts of domestication and improvement on multiple characteristics of the fruit.
Summary Citrus come in diverse sizes and shapes, and play a key role in world culture and economy. Citrus oil glands in particular contain essential oils which include plant secondary metabolites associated with flavor and aroma. Capturing and analyzing nuanced information behind the citrus fruit shape and its oil gland distribution provide a morphology‐driven path to further our insight into phenotype–genotype interactions.
We investigated the shape of citrus fruit of 51 accessions based on 3D X‐ray computed tomography (CT) scan reconstructions. Accessions include members of the three ancestral citrus species as well as related genera, and several interspecific hybrids. We digitally separate and compare the size of fruit endocarp, mesocarp, exocarp, and oil gland tissue. Based on the centers of the oil glands, overall fruit shape is approximated with an ellipsoid. Possible oil gland distributions on this ellipsoid surface are explored using directional statistics.
There is a strong allometry along fruit tissues; that is, we observe a strong linear relationship between the logarithmic volume of any pair of major tissues. This suggests that the relative growth of fruit tissues with respect to each other follows a power law. We also observe that on average, glands distance themselves from their nearest neighbor following a square root relationship, which suggests normal diffusion dynamics at play.
The observed allometry and square root models point to the existence of biophysical developmental constraints that govern novel relationships between fruit dimensions from both evolutionary and breeding perspectives. Understanding these biophysical interactions prompts an exciting research path on fruit development and breeding.
