Studying the effects of serpentine soil on adapted and non-adapted species using Arduino technology

Abstract: Serpentine soils are formed from ultramafic rocks and are represent an extreme environment for plants. Serpentine soils are unique in that they carry high concentrations of heavy metals, are nutrient deficient, particularly in calcium, and have poor water retention capabilities. Although these soils constitute harsh conditions for plant growth, there are a number of species that are adapted and even endemic to serpentine soil. Water retention by commercial potting mix was compared with serpentine soil. Also, serpentine adapted and non-adapted species were grown in both soil treatments and physiological data were collected. We used the Arduino electronic platform to collect data such as moisture levels and photosynthetic activity. An advantage of Arduino-based data collection is low cost and the availability of a wide array of sensors. An Arduino-based cartesian coordinate robotic system was created to automate data collection from a set of small potted plants in a grid formation

The expression pattern of the tonoplast intrinsic protein γ-TIP in Arabidopsis thaliana Is correlated with cell enlargement

The vacuolar membrane (tonoplast) contains an abundant intrinsic protein with six membrane-spanning domains that is encoded by a small gene family. Different isoforms of tonoplast intrinsic protein (TIP) are expressed in different tissues or as a result of specific signals. Using promoter-beta-glucuronidase (GUS) fusions and in situ hybridization, we have examined the expression of gamma-TIP in Arabidopsis thaliana. GUS staining of plants transformed with promoter-GUS fusions showed that gamma-TIP gene expression is high in recently formed tissues of young roots. In the shoot, gamma-TIP gene expression was highest in the vascular bundles of stems and petioles, as well as in the stipules and in the receptacle of the flower. No GUS activity was detected in root or shoot meristems or in older tissues, suggesting temporal control of gamma-TIP gene expression associated with cell elongation and/or differentiation. In situ hybridization carried out with whole seedlings confirmed that in root tips, gamma-TIP mRNA was present only in the zone of cell elongation just behind the apical meristem. In seedling shoots, mRNA abundance was also found to be correlated with cell expansion. These results indicate that gamma-TIP may be expressed primarily at the time when the large central vacuoles are being formed during cell enlargement.Supported by a grant from the United States Department of Agriculture (to M.J.C.), a European Molecular Biology Organization fellowship (to H.H.), and a fellowship from the Provincial Government of Catalonia (to D.L.).Peer reviewe

An Albino Mutant in Brassica rapa Maps to the PDX2 Locus on Chromosome 10

We have identified an albino mutant in the plant Brassica rapa. This recessive mutation could provide insights into the photosynthetic pathways of all plants. Previously the mutation was mapped to chromosome 10 of Brassica rapa. To narrow down the chromosomal region containing the albino mutation, we grew a segregating population of plants. DNA was extracted from albino and wildtype (green) plants and genotyped using PCR markers on chromosome 10. The genotype detected using the INDEL2 marker perfectly predicted whether a plant was albino or WT. This indicates that the INDEL2 marker is tightly linked to the albino mutation. INDEL2 is near the gene PDX2 and we detected a single nucleotide change near the PDX2 gene that is only found in albino plants. It is possible that this mutation affects expression of PDX2 and is the cause of the albino phenotype. PDX2 is involved in vitamin B6 synthesis and it is unclear how altering vitamin metabolism could affect photosynthesis

Forward and Reverse Genetics of Rapid-Cycling \u3cem\u3eBrassica oleracea\u3c/em\u3e

Seeds of rapid-cycling Brassica oleracea were mutagenized with the chemical mutagen, ethylmethane sulfonate. The reverse genetics technique, TILLING, was used on a sample population of 1,000 plants, to determine the mutation profile. The spectrum and frequency of mutations induced by ethylmethane sulfonate was similar to that seen in other diploid species such as Arabidopsis thaliana. These data indicate that the mutagenesis was effective and demonstrate that TILLING represents an efficient reverse genetic technique in B. oleracea that will become more valuable as increasing genomic sequence data become available for this species. The extensive duplication in the B. oleracea genome is believed to result in the genetic redundancy that has been important for the evolution of morphological diversity seen in today\u27s B. oleracea crops (broccoli, Brussels sprouts, cauliflower, cabbage, kale and kohlrabi). However, our forward genetic screens identified 120 mutants in which some aspect of development was affected. Some of these lines have been characterized genetically and in the majority of these, the mutant trait segregates as a recessive allele affecting a single locus. One dominant mutation (curly leaves) and one semi-dominant mutation (dwarf-like) were also identified. Allelism tests of two groups of mutants (glossy and dwarf) revealed that for some loci, multiple independent alleles have been identified. These data indicate that, despite genetic redundancy, mutation of many individual loci in B. oleracea results in distinct phenotypes

Forward and reverse genetics of rapid-cycling Brassica oleracea

Abstract Seeds of rapid-cycling Brassica oleracea were mutagenized with the chemical mutagen, ethylmethane sulfonate. The reverse genetics technique, TILLING, was used on a sample population of 1,000 plants, to determine the mutation proWle. The spectrum and frequency of mutations induced by ethylmethane sulfonate was similar to that seen in other diploid species such as Arabidopsis thaliana. These data indicate that the mutagenesis was eVective and demonstrate that TILLING represents an eYcient reverse genetic technique in B. oleracea that will become more valuable as increasing genomic sequence data become available for this species. The extensive duplication in the B. oleracea genome is believed to result in the genetic redundancy that has been important for the evolution of morphological diversity seen in today's B. oleracea crops (broccoli, Brussels sprouts, cauliXower, cabbage, kale and kohlrabi). However, our forward genetic screens identiWed 120 mutants in which some aspect of development was aVected. Some of these lines have been characterized genetically and in the majority of these, the mutant trait segregates as a recessive allele aVecting a single locus. One dominant mutation (curly leaves) and one semi-dominant mutation (dwarf-like) were also identiWed. Allelism tests of two groups of mutants (glossy and dwarf) revealed that for some loci, multiple independent alleles have been identiWed. These data indicate that, despite genetic redundancy, mutation of many individual loci in B. oleracea results in distinct phenotypes

Delivering Copper Within Plant Cells

Two genes recently identified in Arabidopsis thaliana may be involved in sequestering free copper ions in the cytoplasm and delivering copper to post-Golgi vesicles. The genes COPPER CHAPERONE and RESPONSIVE TO ANTAGONIST1 are homologous to copper-trafficking genes from yeast and humans. This plant copper-delivery pathway is required to create functional ethylene receptors. The pathway may also facilitate the transport of copper from senescing leaf tissue. In addition, several other genes have been identified recently that may have a role in copper salvage during senescence

The Expression Pattern of the Tonoplast Intrinsic Protein γ-TIP in \u3cem\u3eArabidopsis thaliana\u3c/em\u3e Is Correlated With Cell Enlargement

The vacuolar membrane (tonoplast) contains an abundant intrinsic protein with six membrane-spanning domains that is encoded by a small gene family. Different isoforms of tonoplast intrinsic protein (TIP) are expressed in different tissues or as a result of specific signals. Using promoter-β-glucuronidase (GUS) fusions and in situ hybridization, we have examined the expression of γ-TIP in Arabidopsis thaliana. GUS staining of plants transformed with promoter-GUS fusions showed that γ-TIP gene expression is high in recently formed tissues of young roots. In the shoot, γ-TIP gene expression was highest in the vascular bundles of stems and petioles, as well as in the stipules and in the receptacle of the flower. No GUS activity was detected in root or shoot meristems or in older tissues, suggesting temporal control of γ-TIP gene expression associated with cell elongation and/or differentiation. In situ hybridization carried out with whole seedlings confirmed that in root tips, γ-TIP mRNA was present only in the zone of cell elongation just behind the apical meristem. In seedling shoots, mRNA abundance was also found to be correlated with cell expansion. These results indicate that γ-TIP may be expressed primarily at the time when the large central vacuoles are being formed during cell enlargement

Molecular Aspect of Leaf Senescence

Senescence is the last stage of leaf development and one type of programmed cell death that occurs in plants. The relationships among senescence programs that are induced by a variety of factors have been addressed at a molecular level in recent studies. Furthermore, an overlap between the pathogen-response and senescence programs is beginning to be characterized. The complexity of the senescence program is also evident in studies of senescence-specific gene regulation and the role of photosynthesis and plant hormones in senescence regulation. New molecular-genetic approaches are expected to be useful in unraveling the molecular mechanisms of the leaf senescence program