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PubMed2005

Kenneth Frank Baker--pioneer leader in plant pathology.

Kenneth F. Baker (1908-1996) made major contributions to understanding diseases of ornamental plants, seed pathology, soil-borne plant pathogens, biological control, and history of plant pathology. His work set the stage for the success of today's ornamentals and nursery industries. His leadership and writings created the scientific framework for research and teaching on soil-borne plant pathogens and biological control. After B.Sc. and Ph.D. degrees from Washington State University in 1930 and 1934, respectively, and one year as a National Research Council Fellow with B.M. Dugger at Wisconsin, he took jobs in 1935 with the U.S. Department of Agriculture in Nebraska on establishment of shelter belts and 1936-39 with the Pineapple Producers Cooperative Association in Hawaii. He worked on diseases of ornamental plants at the University of California, Los Angeles, starting in 1939, moving to Berkeley in 1961 when the UCLA program closed. He retired in 1975 and moved to Corvallis, OR, as Emeritus Professor, Oregon State University, and Collaborator, U.S. Department of Agriculture, Agricultural Research Service. He spent four sabbatical leaves in Australia, and was elected fellow of the American Association for the Advancement of Science in 1950, fellow of the American Phytopathological Society in 1969, and the Horticultural Hall of Fame in 1976.

Botany↗
PubMed2004

The accidental plant pathologist.

This article presents the experiences of a woman in academic plant pathology from the 1950s to today. Topics include the social climate for women in science, personal and professional developments and research discoveries, public policy issues in agriculture and biotechnology affecting plant pathology, and projections for the future of plant pathology.

Austria↗
PubMed2005

Being at the right place, at the right time, for the right reasons--plant pathology.

This article relates some personal history and influences leading to becoming a plant pathologist. Next a summary of my research experiences on rice and barley diseases and the effect of regulatory changes on efforts to manage rice diseases in California. I conclude with an invitation to consider the opportunities and obligations of plant pathologists to return to the field and for individual introspection regarding attitudes and behavior toward colleagues and factors affecting our profession.

Botany↗
PubMed1992

Life in space.

Explore the source record for details and available documents.

Biological Science Disciplines↗
PubMed2005

Discovery of the photosynthetic relatives of the "Maltese mushroom" Cynomorium.

BACKGROUND: Although recent molecular phylogenetic studies have identified the photosynthetic relatives of several enigmatic holoparasitic angiosperms, uncertainty remains for the last parasitic plant order, Balanophorales, often considered to include two families, Balanophoraceae and Cynomoriaceae. The nonphotosynthetic (holoparasitic) flowering plant Cynomorium coccineum has long been known to the Muslim world as "tarthuth" and to Europeans as the "Maltese mushroom"; C. songaricum is known in Chinese medicine as "suo yang." Interest in these plants is increasing and they are being extensively collected from wild populations for use in herbal medicines. RESULTS: Here we report molecular phylogenetic analyses of nuclear ribosomal DNA and mitochondrial matR sequence data that strongly support the independent origin of Balanophoraceae and Cynomoriaceae. Analyses of single gene and combined gene data sets place Cynomorium in Saxifragales, possibly near Crassulaceae (stonecrop family). Balanophoraceae appear related to Santalales (sandalwood order), a position previously suggested from morphological characters that are often assumed to be convergent. CONCLUSION: Our work shows that Cynomorium and Balanophoraceae are not closely related as indicated in all past and present classifications. Thus, morphological features, such as inflorescences bearing numerous highly reduced flowers, are convergent and were attained independently by these two holoparasite lineages. Given the widespread harvest of wild Cynomorium species for herbal medicines, we here raise conservation concerns and suggest that further molecular phylogenetic work is needed to identify its photosynthetic relatives. These relatives, which will be easier to cultivate, should then be examined for phytochemical activity purported to be present in the more sensitive Cynomorium.

Bayes Theorem↗
PubMed2007

A multi-treatment experimental system to examine photosynthetic differentiation in the maize leaf.

BACKGROUND: The establishment of C4 photosynthesis in maize is associated with differential accumulation of gene transcripts and proteins between bundle sheath and mesophyll photosynthetic cell types. We have physically separated photosynthetic cell types in the leaf blade to characterize differences in gene expression by microarray analysis. Additional control treatments were used to account for transcriptional changes induced by cell preparation treatments. To analyse these data, we have developed a statistical model to compare gene expression values derived from multiple, partially confounded, treatment groups. RESULTS: Differential gene expression in the leaves of wild-type maize seedlings was characterized using the latest release of a maize long-oligonucleotide microarray produced by the Maize Array Project consortium. The complete data set is available through the project web site. Data is also available at the NCBI GEO website, series record GSE3890. Data was analysed with and without consideration of cell preparation associated stress. CONCLUSION: Empirical comparison of the two analyses suggested that consideration of stress helped to reduce the false identification of stress responsive transcripts as cell-type enriched. Using our model including a stress term, we identified 8% of features as differentially expressed between bundle sheath and mesophyll cell types under control of false discovery rate of 5%. An estimate of the overall proportion of differentially accumulating transcripts (1-pi0) suggested that as many as 18% of the genes may be differentially expressed between B and M. The analytical model presented here is generally applicable to gene expression data and demonstrates the use of statistical elimination of confounding effects such as stress in the context of microarray analysis. We discuss the implications of the high degree of differential transcript accumulation observed with regard to both the establishment and engineering of the C4 syndrome.

Botany↗
PubMed2005

Design and fabrication of adjustable red-green-blue LED light arrays for plant research.

BACKGROUND: Although specific light attributes, such as color and fluence rate, influence plant growth and development, researchers generally cannot control the fine spectral conditions of artificial plant-growth environments. Plant growth chambers are typically outfitted with fluorescent and/or incandescent fixtures that provide a general spectrum that is accommodating to the human eye and not necessarily supportive to plant development. Many studies over the last several decades, primarily in Arabidopsis thaliana, have clearly shown that variation in light quantity, quality and photoperiod can be manipulated to affect growth and control developmental transitions. Light emitting diodes (LEDs) has been used for decades to test plant responses to narrow-bandwidth light. LEDs are particularly well suited for plant growth chambers, as they have an extraordinary life (about 100,000 hours), require little maintenance, and use negligible energy. These factors render LED-based light strategies particularly appropriate for space-biology as well as terrestrial applications. However, there is a need for a versatile and inexpensive LED array platform where individual wavebands can be specifically tuned to produce a series of light combinations consisting of various quantities and qualities of individual wavelengths. Two plans are presented in this report. RESULTS: In this technical report we describe the practical construction of tunable red-green-blue LED arrays to support research in plant growth and development. Two light fixture designs and corresponding circuitry are presented. The first is well suited for a laboratory environment for use in a finite area with small plants, such as Arabidopsis. The second is expandable and appropriate for growth chambers. The application of these arrays to early plant developmental studies has been validated with assays of hypocotyl growth inhibition/promotion and phototropic curvature in Arabidopsis seedlings. CONCLUSION: The presentation of these proven plans for LED array construction allows the teacher, researcher or electronics aficionado a means to inexpensively build efficient, adjustable lighting modules for plant research. These simple and effective designs permit the construction of useful tools by programs short on electronics expertise. These arrays represent a means to modulate precise quality and quantity in experimental settings to test the effect of specific light combinations in regulating plant growth, development and plant-product yield.

Arabidopsis↗
PubMed2005

A fully automatable enzymatic method for DNA extraction from plant tissues.

BACKGROUND: DNA extraction from plant tissues, unlike DNA isolation from mammalian tissues, remains difficult due to the presence of a rigid cell wall around the plant cells. Currently used methods inevitably require a laborious mechanical grinding step, necessary to disrupt the cell wall for the release of DNA. RESULTS: Using a cocktail of different carbohydrases, a method was developed that enables a complete digestion of the plant cell walls and subsequent DNA release. Optimized conditions for the digestion reaction minimize DNA shearing and digestion, and maximize DNA release from the plant cell. The method gave good results in 125 of the 156 tested species. CONCLUSION: In combination with conventional DNA isolation techniques, the new enzymatic method allows to obtain high-yield, high-molecular weight DNA, which can be used for many applications, including genome characterization by AFLP, RAPD and SSR. Automation of the protocol (from leaf disks to DNA) is possible with existing workstations.

Botany↗
PubMed2005

Maize in pre-Columbian China.

A certain Chinese herbal book presented to the emperor in 1505 shows a drawing of maize under the caption of Yiyi-ren (Job's Tears). Also, a Chinese poem written around 1368 contains a term yumi, which indicates maize. These new findings offer clear evidence that maize existed in China in the pre-Columbian era, or before 1492. Details of this evidence are discussed here.

Books, Illustrated↗
PubMed2006

[Maize in pre-columbian China found in Bencao Pinhui Jingyao].

Bencao Pinhui Jingyao complied in 1505 shows a drawing of maize under the caption of Yiyi-ren (Job's Tear). Also, a Chinese poem written around 1368 contains a term yumi, which indicates maize. These new findings offer clear evidence that maize existed in China in the pre-Columbian era. Details of this evidence, together with probable routes of introduction of maize to China, are discussed here.

Botany↗
PubMed2006

[Presence of pre-Columbian maize in the Old World--an overview].

An overview is presented on the reports available so far on pre-Columbian maize covering the regions of India, Mideast, Africa and Iberia. Frequent observations of maize recorded in the past on the East and the West Coast of Africa and at the ports in the Mideast show that maize was one of the staples of the natives well before 1492. It is also evident that maize in the West Africa was disseminated to Iberia and Lombardy in the pre-Columbian time. An earlier contact between the Old and the New World is strongly suggested.

Africa↗
PubMed1995

[Production of medicinal plants by soilless culture system. I. Studies of morphological characteristics and saikosaponins content in Bupleurum falcatum cultivated by Ebb & Flood system].

We studied that the morphological and histological characteristics, and the content (%DW) of saikosaponins on the root of Bupleurum falcatum cultivated in an Ebb & Flood system (E & F), a kind of soilless culture system, by both the direct sowing and the transplanting methods, and that effects of pinching on the root growth and the content (%DW) of saikosaponins in each part of root. Yield of root and content (%DW) of saikosaponins in each part of root, 8-months-old, cultivated in E & F by both methods were at the same level as that cultivated for the same period in soil condition by generally standard procedures. Morphological characteristics of the root cultivated by the direct sowing method were the same appearance as that by soil condition, but by the transplanting method main root branched off in all direction and the lateral root were more developed than by the direct sowing method. By pinching lignification in xylem on the main root were inhibited, but the dried weight of total root part and content (%DW) of saikosaponins in each part of the root were not shown to be significantly changed.

Botany↗