Arabidopsis thaliana, the thale cress, mouse-ear cress or arabidopsis, is a small plant from the mustard family (Brassicaceae), native to Eurasia and Africa. Commonly found along the shoulders of roads and in disturbed land, it is generally considered a weed.
The transfer DNA is the transferred DNA of the tumor-inducing (Ti) plasmid of some species of bacteria such as Agrobacterium tumefaciens and Agrobacterium rhizogenes . The T-DNA is transferred from bacterium into the host plant's nuclear DNA genome. The capability of this specialized tumor-inducing (Ti) plasmid is attributed to two essential regions required for DNA transfer to the host cell. The T-DNA is bordered by 25-base-pair repeats on each end. Transfer is initiated at the right border and terminated at the left border and requires the vir genes of the Ti plasmid.
Hydrotropism is a plant's growth response in which the direction of growth is determined by a stimulus or gradient in water concentration. A common example is a plant root growing in humid air bending toward a higher relative humidity level.
The ABC model of flower development is a scientific model of the process by which flowering plants produce a pattern of gene expression in meristems that leads to the appearance of an organ oriented towards sexual reproduction, a flower. There are three physiological developments that must occur in order for this to take place: firstly, the plant must pass from sexual immaturity into a sexually mature state ; secondly, the transformation of the apical meristem's function from a vegetative meristem into a floral meristem or inflorescence; and finally the growth of the flower's individual organs. The latter phase has been modelled using the ABC model, which aims to describe the biological basis of the process from the perspective of molecular and developmental genetics.
A primordium in embryology, is an organ or tissue in its earliest recognizable stage of development. Cells of the primordium are called primordial cells. A primordium is the simplest set of cells capable of triggering growth of the would-be organ and the initial foundation from which an organ is able to grow. In flowering plants, a floral primordium gives rise to a flower.
Aspartate kinase or aspartokinase (AK) is an enzyme that catalyzes the phosphorylation of the amino acid aspartate. This reaction is the first step in the biosynthesis of three other amino acids: methionine, lysine, and threonine, known as the "aspartate family". Aspartokinases are present only in microorganisms and plants, but not in animals, which must obtain aspartate-family amino acids from their diet. Consequently, methionine, lysine and threonine are essential amino acids in animals.
Leptosphaeria maculans is a fungal pathogen of the phylum Ascomycota that is the causal agent of blackleg disease on Brassica crops. Its genome has been sequenced, and L. maculans is a well-studied model phytopathogenic fungus. Symptoms of blackleg generally include basal stem cankers, small grey lesions on leaves, and root rot. The major yield loss is due to stem canker. The fungus is dispersed by the wind as ascospores or rain splash in the case of the conidia. L. maculans grows best in wet conditions and a temperature range of 5–20 degrees Celsius. Rotation of crops, removal of stubble, application of fungicide, and crop resistance are all used to manage blackleg. The fungus is an important pathogen of Brassica napus (canola) crops.
The acetolactate synthase (ALS) enzyme is a protein found in plants and micro-organisms. ALS catalyzes the first step in the synthesis of the branched-chain amino acids.
Plant genetics is the study of genes, genetic variation, and heredity specifically in plants. It is generally considered a field of biology and botany, but intersects frequently with many other life sciences and is strongly linked with the study of information systems. Plant genetics is similar in many ways to animal genetics but differs in a few key areas.
Somatic recombination, as opposed to the genetic recombination that occurs in meiosis, is an alteration of the DNA of a somatic cell that is inherited by its daughter cells. The term is usually reserved for large-scale alterations of DNA such as chromosomal translocations and deletions and not applied to point mutations. Somatic recombination occurs physiologically in the assembly of the B cell receptor and T-cell receptor genes, as well as in the class switching of immunoglobulins. Somatic recombination is also important in the process of carcinogenesis.
HOTHEAD is an Arabidopsis thaliana gene that encodes a flavin adenine dinucleotide-containing oxidoreductase. This gene has a role in the creation of the carpel during the formation of flowers through the fusion of epidermal cells. Observations of reversion of the hothead phenotype and genotype led to the suggestion that the plants were able to "remember" the sequences of genes present in their ancestors, possibly through a cache of complementary RNA. This report attracted broad attention, and alternative explanations were suggested. Later research suggested that the supposed reversion phenomenon was due to the plants having a pronounced bias towards outcrossing, rather than self-fertilizing at high rates, as is typical for A. thaliana.
In biology, phototropism is the growth of an organism in response to a light stimulus. Phototropism is most often observed in plants, but can also occur in other organisms such as fungi. The cells on the plant that are farthest from the light contain a hormone called auxin that reacts when phototropism occurs. This causes the plant to have elongated cells on the furthest side from the light. Phototropism is one of the many plant tropisms, or movements, which respond to external stimuli. Growth towards a light source is called positive phototropism, while growth away from light is called negative phototropism. Negative phototropism is not to be confused with skototropism, which is defined as the growth towards darkness, whereas negative phototropism can refer to either the growth away from a light source or towards the darkness. Most plant shoots exhibit positive phototropism, and rearrange their chloroplasts in the leaves to maximize photosynthetic energy and promote growth. Some vine shoot tips exhibit negative phototropism, which allows them to grow towards dark, solid objects and climb them. The combination of phototropism and gravitropism allow plants to grow in the correct direction.
Vegetative phase change is the juvenile-to-adult transition in plants. This transition is distinct from the reproductive transition and is most prolonged and pronounced in woody species. Manipulating phase change may be an important avenue for plant improvement.
All-trans-nonaprenyl diphosphate synthase is an enzyme with systematic name geranylgeranyl-diphosphate:isopentenyl-diphosphate transtransferase . This enzyme catalyses the following chemical reaction
Li Jiayang is a Chinese agronomist and geneticist. He is Vice Minister of Agriculture in China and President of the Chinese Academy of Agricultural Sciences (CAAS). He is also Professor and Principal investigator at the Institute of Genetics and Development at the Chinese Academy of Sciences (CAS).
LUX or Phytoclock1 (PCL1) is a gene that codes for LUX ARRHYTHMO, a protein necessary for circadian rhythms in Arabidopsis thaliana. LUX protein associates with Early Flowering 3 (ELF3) and Early Flowering 4 (ELF4) to form the Evening Complex (EC), a core component of the Arabidopsis repressilator model of the plant circadian clock. The LUX protein functions as a transcription factor that negatively regulates Pseudo-Response Regulator 9 (PRR9), a core gene of the Midday Complex, another component of the Arabidopsis repressilator model. LUX is also associated with circadian control of hypocotyl growth factor genes PHYTOCHROME INTERACTING FACTOR 4 (PIF4) and PHYTOCHROME INTERACTING FACTOR 5 (PIF5).
Arabidopsis thaliana is a first class model organism and the single most important species for fundamental research in plant molecular genetics.
Christopher Roland Somerville is a Canadian-American biologist known as a pioneer of Arabidopsis thaliana research. Somerville is currently Professor Emeritus at the University of California, Berkeley and a Program Officer at the Open Philanthropy Project.
As a model organism, the Arabidopsis thaliana response to salinity is studied to aid understanding of other more economically important crops.
Decreased DNA Methylation I (DDM1), is a plant gene that encodes a nucleosome remodeler which facilitates DNA methylation. The DDM1 gene has been described extensively in Arabidopsis thaliana and also in maize. The protein has been described to be similar to the SWI2/SNF2 chromatin remodeling proteins.
