Specific attraction to and infection of cotton root cap cells by zoospores of Pythium dissotocum

1989 ◽  
Vol 67 (6) ◽  
pp. 1760-1767 ◽  
Author(s):  
N. P. Goldberg ◽  
M. C. HAwes ◽  
M. E. Stanghellini
Keyword(s):  
Living Cells ◽  
Gossypium Barbadense ◽  
Root Cap ◽  
Chemotactic Response ◽  
Agrostis Palustris ◽  
Isolated Cells ◽  
Cotton Species ◽  
Pythium Dissotocum ◽  
Zoospore Suspension ◽  
Individual Root

Root cap cells of two cotton species (Gossypium barbadense L. and G. hirsutum L.) elicited a specific chemotactic response in zoospores of Pythium dissotocum. When roots of cotton seedlings were placed into a suspension of Pythium dissotocum zoospores, there was immediate attraction, accumulation, and encystment exclusively in the root cap region. Seedlings which attracted zoospores were killed within 24 h. Furthermore, root cap cells remained attractive when isolated nondestructively from the root and placed into a zoospore suspension; attraction, accumulation, and encystment on individual root cap cells occurred within seconds after contact. Penetration and death of isolated cells occurred within 15–30 min. After 30 min, approximately 25% of living cells were directly colonized by zoospores. Root cap cells killed by freezing or drying remained attractive but at a reduced level; approximately half as many killed cells as living cells were directly colonized by zoospores. The number of root cap cells directly colonized by zoospores did not increase with time. In contrast, zoospores of Pythium catenulatum that exhibited a chemotactic response to Agrostis palustris (Bentgrass) were not attracted to and did not infect cotton seedlings or isolated root cap cells.

Association between Alternaria macrospora and Alternaria alternata, causal agents of cotton leaf blight

1991 ◽  
Vol 69 (12) ◽  
pp. 2603-2607 ◽  
Author(s):  
Yoav Bashan ◽  
Hanna Levanony ◽  
Reuven Or
Keyword(s):  
Gossypium Hirsutum ◽  
Alternaria Alternata ◽  
Leaf Surface ◽  
Gossypium Barbadense ◽  
Cotton Leaf ◽  
Optimal Dosage ◽  
Alternaria Blight ◽  
Cotton Species ◽  
Infested Field ◽  
Blight Disease

The association between Alternaria macrospora and Alternaria alternata, responsible for the development of alternaria blight disease in cotton, was evaluated in artificially inoculated greenhouse plants and in naturally infested field plants. When greenhouse plants were inoculated with suboptimal doses of both pathogens (< 1.2 × 104 spores/mL) infection was greater than when separately inoculated by each pathogen at optimal dosage. In field-grown, naturally infected plants (Gossypium barbadense), both pathogens were found together in more than 40% of the plants. A second field-grown cotton species (Gossypium hirsutum) exhibited infection mainly by either A. alternata or both pathogens together. When both cotton species were naturally infected by both pathogens together, the number of A. alternata spores (either airborne or on the leaf surface) was greater than that of A. macrospora. We propose that A. macrospora together with A. alternata create a disease composite responsible for alternaria blight symptoms in cotton. Key words: Alternaria, cotton diseases, Gossypium barbadense, Gossypium hirsutum.

Mucilage production by wounded xylem tissue of maize roots — time course and stimulus

2003 ◽  
Vol 30 (7) ◽  
pp. 755 ◽  
Author(s):  
Laura J. Crews ◽  
Margaret E. McCully ◽  
Martin J. Canny
Keyword(s):  
Time Course ◽  
Living Cells ◽  
Root Cap ◽  
Experimental Investigations ◽  
Mechanical Wounding ◽  
Maize Roots ◽  
Acidic Polysaccharides ◽  
Xylem Tissue ◽  
Xylem Conduits ◽  
Xylem Function

As a reaction to invasion by pathogens, plants block their xylem conduits with mucilage, restricting pathogen advance. Wounding soil-grown roots of maize revealed that pectinaceous mucilage could be found in the vessels after 6 h, and abundantly filled most vessels up to 3 cm proximal to the wound after 1 d. Phenolics increased in the mucilage at later times. The same reactions occurred in vessels following mechanical wounding of axenically-grown roots, showing that the presence of microbes is not necessary for the response. The xylem mucilage is similar to root-cap mucilage in mode of extrusion from the periplasmic space of living cells through primary wall, apparent phase transition, and staining indicative of acidic polysaccharides. Whether other known properties of root-cap mucilage which might alter vessel functioning, such as reduction of surface tension and increased viscosity produced by dissolved solutes, are also common to xylem mucilage requires further investigation. However, our results indicate that possible influence of wounding-induced mucilage in xylem vessels should be considered in all experimental investigations of xylem function.

Effects of D-galactose on the ultrastructure of bentgrass root apices

1968 ◽  
Vol 46 (4) ◽  
pp. 391-395 ◽  
Author(s):  
R. M. Endo ◽  
W. W. Thomson ◽  
Emmylou M. Krausman
Keyword(s):  
Cell Wall ◽  
Cell Plate ◽  
Root Cap ◽  
Agrostis Palustris ◽  
Thin Sections ◽  
Cellular Processes ◽  
Growth Inhibitory ◽  
Apparent Reduction ◽  
And Function ◽  
Root Apices

To study the effects of growth-inhibitory concentrations of D-galactose on the morphology and function of organelles, thin sections of galactose-treated, KMnO4-fixed bentgrass (Agrostis palustris L.) root apices were examined in the electron microscope. Inhibitory effects were noted on root cap mucilage formation, cell plate formation, cell wall accretion, and the organelles associated with these processes such as the dictyosomes and the endoplasmic reticulum. These studies suggest that D-galactose inhibits root elongation by not only suppressing the synthesis of cell wall precursors—as evidenced by apparent reduction in the activity of the dictyosomes and root cap mucilage formation—but also the cellular processes involved in cell wall accretion and the formation of the cell plate.

Construction and characterization of the first bacterial artificial chromosome library for the cotton species Gossypium barbadense L.

Genome ◽  
2006 ◽  
Vol 49 (11) ◽  
pp. 1393-1398 ◽  
Author(s):  
X.F. Wang ◽  
J. Ma ◽  
W.S. Wang ◽  
Y.M. Zheng ◽  
G.Y. Zhang ◽  
...  
Keyword(s):  
Bacterial Artificial Chromosome ◽  
Bac Library ◽  
Artificial Chromosome ◽  
Gossypium Barbadense ◽  
Average Insert Size ◽  
Insert Size ◽  
Breeding Programs ◽  
Fiber Properties ◽  
Cotton Species

As the second most widely cultivated cotton, Gossypium barbadense is well known for its superior fiber properties and its high levels of resistance to Fusarium and Verticillium wilts. To enhance our ability to exploit these properties in breeding programs, we constructed the first bacterial artificial chromosome (BAC) library for this species. The library contains 167 424 clones (49 920 BamHI and 117 504 HindIII clones), with an estimated average insert size of 130 kb. About 94.0% of the clones had inserts over 100 kb, and the empty clones accounted for less than 4.0%. Contamination of the library with chloroplast clones was very low (0.2%). Screening the library with locus-specific probes showed that BAC clones represent 6.5-fold genome equivalents. This high-quality library provides an additional asset with which to exploit genetic variation for cotton improvement.

scholarly journals The Chalcone Isomerase Family in Cotton: Whole-Genome Bioinformatic and Expression Analyses of the Gossypium barbadense L. Response to Fusarium Wilt Infection

Genes ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1006 ◽  
Author(s):  
Qian-Li Zu ◽  
Yan-Ying Qu ◽  
Zhi-Yong Ni ◽  
Kai Zheng ◽  
Qin Chen ◽  
...  
Keyword(s):  
Gene Family ◽  
Fusarium Wilt ◽  
Pairwise Comparison ◽  
Gossypium Barbadense ◽  
Chalcone Isomerase ◽  
Whole Genome ◽  
Systematic Analysis ◽  
Preliminary Model ◽  
Cotton Species ◽  
Duplication Events

Chalcone isomerase (CHI) is a key component of phenylalanine metabolism that can produce a variety of flavonoids. However, little information and no systematic analysis of CHI genes is available for cotton. Here, we identified 33 CHI genes in the complete genome sequences of four cotton species (Gossypium arboretum L., Gossypium raimondii L., Gossypium hirsutum L., and Gossypium barbadense L.). Cotton CHI proteins were classified into two main groups, and whole-genome/segmental and dispersed duplication events were important in CHI gene family expansion. qRT-PCR and semiquantitative RT-PCR results suggest that CHI genes exhibit temporal and spatial variation and respond to infection with Fusarium wilt race 7. A preliminary model of CHI gene involvement in cotton evolution was established. Pairwise comparison revealed that seven CHI genes showed higher expression in cultivar 06-146 than in cultivar Xinhai 14. Overall, this whole-genome identification unlocks a new approach to the comprehensive functional analysis of the CHI gene family, which may be involved in adaptation to plant pathogen stress.

MORPHOLOGY AND BREEDING BEHAVIOR OF COTTON HAPLOIDS

1976 ◽  
Vol 18 (4) ◽  
pp. 673-678
Author(s):  
H. K. Chaudhari
Keyword(s):  
Genetic Marker ◽  
Gossypium Barbadense ◽  
Breeding Behavior ◽  
Cotton Species ◽  
Fruit Setting

Haploids of two cotton species Gossypium barbadense L. andG. hirsutum L. were produced by using the semigametic strain VSg-7. They were identified by a genetic marker, Miniature stature, their small leaves and flowers, and anther indehiscence. Haploids and diploids differed significantly from each other in seven characteristics and the differences in four of them were close to 2:1, the same as the chromosome ratio. Haploids of G. hirsutum were completely sterile, while those of G. barbadense showed some fertility as evidenced by an apparent 2% diads in PMCs, 3% functional pollen, 6% crossing, and fruit-setting in 43% of the haploids.

scholarly journals Observations on the Cytoplasmic Membranes of Testicular Cells, Examined by Phase Contrast and Electron Microscopy

1958 ◽  
Vol 4 (2) ◽  
pp. 135-142 ◽  
Author(s):  
Don W. Fawcett ◽  
Susumu Ito
Keyword(s):  
Endoplasmic Reticulum ◽  
Phase Contrast ◽  
Cell Types ◽  
Living Cells ◽  
Experimental Investigations ◽  
Isolated Cells ◽  
Testicular Cells ◽  
Linear Extent ◽  
Cytoplasmic Membranes ◽  
Myelin Figures

In freshly isolated cells of the guinea pig germinal epithelium examined with phase contrast, dark contours are seen in the cytoplasm that appear to be optical sections of the cisternae of the endoplasmic reticulum. These increase in contrast, in number, and in linear extent with increasing time up to 4 hours after isolation of the cells from the testis. During this period, cisternae originally present in the cells are extended and new ones appear to be formed by coalescence of tubular and vesicular elements of the reticulum. The cisternae become associated in parallel array and ultimately form elaborate concentric systems resembling structures that have often been interpreted as intracellular "myelin figures." Until now our knowledge of the endoplasmic reticulum has been based largely upon electron micrographs. The observation that the cisternae are visible in certain cell types under phase contrast optics opens the way for experimental investigations on the behavior of this class of cytoplasmic membranes in living cells.

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