S -Adenosylmethionine Synthetase 3 Is Important for Pollen Tube Growth

Hong

et al. 2016

Plant Breed. Biotech.

S-adenosylmethionine (SAM) is widely involved in variety of biosynthetic processes. It participates in the methionine (Met) metabolic pathway. SAM synthetase (EC 2.5.1.6) is the main enzyme that creates SAM from Met and adenosine triphosphate. SAMS genes are highly conserved in different species. We have isolated SAMS genes from red algae, Pyropia tenera. It has been reported that SAMS genes can confer abiotic stress-related response and growth of plant organs in other species. To elucidate the function of PtSAMS gene in evolutionary perspective, we analyzed SAMS gene using bioinformatics tools and plant transformation of Arabidopsis.

Section: Discussionmentioning

confidence: 99%

“…MAT3 is one of the 4 S-adenosyl methionine synthetase genes in Arabidopsis and is required pollen germination and pollen tube growth (Lindroth et al 2001;Chen et al 2016). PcSAMS1 and PcSAMS2 have been isolated from Pinus contorta.…”

Section: Amino Acid Sequence Analysis and Alignmentmentioning

confidence: 99%

Characterization of S-adenosylmethionine Synthetase Gene from Red Algae, Pyropia tenera

Hong

et al. 2016

Plant Breed. Biotech.

“…Met metabolism was shown to connect with epigenetic modification. SAM acts as a universal methyl donor, downregulation of SAMS encoding S-adenosylmethionine synthetase was shown to reduce global histone methylation, resulting in developmental abnormalities in rice (Li et al, 2011) and Arabidopsis (Chen et al, 2016). In addition, disruption of Met biosynthesis may also affect the extent of methylation as Met is a SAM precursor.…”

Section: Introductionmentioning

confidence: 99%

Cystathionine beta‐lyase is crucial for embryo patterning and the maintenance of root stem cell niche in Arabidopsis

et al. 2019

Summary The growth and development of roots in plants depends on the specification and maintenance of the root apical meristem. Here, we report the identification of CBL, a gene required for embryo and root development in Arabidopsis, and encodes cystathionine beta‐lyase (CBL), which catalyzes the penultimate step in methionine (Met) biosynthesis, and which also led to the discovery of a previous unknown, but crucial, metabolic contribution by the Met biosynthesis pathway. CBL is expressed in embryos and shows quiescent center (QC)‐enriched expression pattern in the root. cbl mutant has impaired embryo patterning, defective root stem cell niche, stunted root growth, and reduces accumulation of the root master regulators PLETHORA1 (PLT1) and PLT2. Furthermore, mutation in CBL severely decreases abundance of several PIN‐FORMED (PIN) proteins and impairs auxin‐responsive gene expression in the root tip. cbl seedlings also exhibit global reduction in histone H3 Lys‐4 trimethylation (H3K4me3) and DNA methylation. Importantly, mutation in CBL reduces the abundance of H3K4me3 modification in PLT1/2 genes and downregulates their expression. Overexpression of PLT2 partially rescues cbl root meristem defect, suggesting that CBL acts in part through PLT1/2. Moreover, exogenous supplementation of Met also restores the impaired QC activity and the root growth defects of cbl. Taken together, our results highlight the unique role of CBL to maintain the root stem cell niche by cooperative actions between Met biosynthesis and epigenetic modification of key developmental regulators.

“…[102][103][104][105][106] Given their interdependent roles in essential molecular, epigenetic and cellular functions, the polyamine and folate pathways are highly conserved and highly regulated, from yeast to plants and mammals, with sometimes overlooked roles in gametogenesis and fertility. 104,[107][108][109][110][111][112] The substrates for polyamine synthesis are ornithine, which is derived from arginine and proline, and S-adenosylmethione (SAM), which is part of the homocysteine cycle in folate metabolism ( Fig 5). SAM is best known as the methyl donor for all methylation reactions for nucleic acids (DNA, RNAs, including tRNAs), proteins (including histones), lipids and other molecules.…”

mentioning

confidence: 99%

“…In Arabidopsis, the MAT3 S-adenosylmethionine synthase gene is expressed in pollen, with mutants showing reduced pollen tube growth and seed set as well as changes in polyamine biosynthesis, tRNA levels, and histone methylation. 112 In humans, polyamine deficiency results in infertility, which can be corrected with SAM or polyamine supplementation. 104,[121][122][123] In cattle, spermine is essential for acrosomal function.…”

mentioning

confidence: 99%

Do gametes woo? Evidence for non-random unions at fertilization

Nadeau

2017

Preprint

A fundamental tenet of inheritance in sexually reproducing organisms such as humans and laboratory mice is that genetic variants combine randomly at fertilization, thereby ensuring a balanced and statistically predictable representation of inherited variants in each generation. This principle is encapsulated in Mendel's First Law. But exceptions are known. With transmission ratio distortion (TRD), particular alleles are preferentially transmitted to offspring without reducing reproductive productivity. Preferential transmission usually occurs in one sex but not both and is not known to require interactions between gametes at fertilization. We recently discovered, in our work in mice and in other reports in the literature, instances where any of 12 mutant genes bias fertilization, with either too many or too few heterozygotes and too few homozygotes, depending on the mutant gene and on dietary conditions. Although such deviations are usually attributed to embryonic lethality of the under-represented genotypes, the evidence is more consistent with genetically-determined preferences for specific combinations of egg and sperm at fertilization that results in genotype bias without embryo loss. These genes and diets could bias fertilization in at least three not mutually exclusive ways. They could trigger a reversal in the order of meiotic divisions during oogenesis so that the genetics of fertilizing sperm elicits preferential chromatid segregation, thereby dictating which allele remains in the egg versus the 2 nd polar body. Bias could also result from genetic-and diet-induced anomalies in polyamine metabolism on which function of haploid gametes normally depends. Finally, secreted and cell-surface factors in female reproductive organs could control access of sperm to eggs based on their genetic content. This unexpected discovery of genetically-biased fertilization in mice could yield insights about the molecular and cellular interactions between sperm and egg at fertilization, with implications for our understanding of inheritance, reproduction, population genetics, and medical genetics. [298 words]All rights reserved. No reuse allowed without permission.(which was not peer-reviewed) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.The copyright holder for this preprint . http://dx.doi.org/10.1101/127134 doi: bioRxiv preprint first posted online Apr. 13, 2017; 3 Our understanding of inheritance in sexually reproducing organisms assumes, with good evidence, that the combination of egg and sperm at fertilization is largely independent of their genetic content. This equal transmission of alternative alleles through meiosis in heterozygotes ensures a balanced parental genetic contribution to offspring at each generation. Mendel's First Law captures this principle, which is one of the few that applies generally in biology. Independent segregation and random union of gametes at fertilization are foundations of classical, quantitative, population, evolutionary and me...