scholarly journals Regulated Expression of Yeast FLP Recombinase in Plant Cells

2000 ◽  
Author(s):  
Thomas K. Hodges ◽  
David Gidoni
Keyword(s):  
Metal Ions ◽  
Seed Production ◽  
Research Proposal ◽  
Hybrid Seed Production ◽  
Male Sterile ◽  
Site Specific ◽  
Flp Recombinase ◽  
Research Activities ◽  
Recombination System ◽  
Regulated Expression

Research activities in both our laboratories were directed toward development of control of the FLP/frt recombination system for plants. As described in the text of the research proposal, the US lab has been engaged in developing regulatory strategies such as tissue-specific promoters and the steroid-inducible activation of the FLP enzyme while the main research activities in Israel have been directed toward the development and testing of a copper-regulated expression of flp recombinase in tobacco (this is an example of a promoter activation by metal ions). The Israeli lab hat additionally completed experiments of previous studies regarding factors affecting the efficiency of recombinase activity using both a gain-of-function assay (excisional-activation of a gusA marker) and loss of function assay (excision of a rolC marker) in tobacco. Site-specific recombinase systems, in particular the FLP/frt and R/RS systems of yeast and the Cre/lox system of bacteriophage P1, have become an essential component of targeted genetic transformation procedures both in animal and plant organisms. To provide more flexibility in transgene excisions by the recombinase systems as well as gene targeting, and to widen possible applications, the development of controlled or regulated recombination systems is highly desirable and was therefore the subject of this research proposal. There are a few possible mechanisms to regulate expression of a recombinase system. They include: 1) control of the recombination system by having the target sites (e.g. frt) in one plant and the flp recombinase gene in another, and bringing the two together by cross fertilization. 2) regulation of promoter activities by external stimuli such as temperature, chemicals, metal ions, etc. 3) regulation of promoter activities by internal signals, i.e. cell- or tissue-specific, or developmental regulation. 4) regulation of enzyme activity by providing cofactors essential for biochemical reactions to take place such as steroid molecules in conjunction with a steroid ligand-binding protein (domains). During the course of this research our major emphasis have been focused toward studying the feasibility of hybrid seed production in Arabidopsis, using FLP/frt. Male-sterility was induced using the antisence of a pollen- and tapetum-specific gene, bcp1, isolated from Arabidopsis. The sterility inducing gene was flanked by frt sites. Upon cross pollination of flowers of male-sterile plants with pollen from FLP-containing plants, viable seeds were produced, and the progeny hybrid plants developed normally. The major achievement from this work is the first demonstration of using a site-specific recombinase to restore fertility in male-sterile plants (see attached paper, Luo et al., Plant J 2000; 23:423-430). The implication from this finding is that site-specific recombination systems can be applied in crop plants as a useful alternative method for hybrid seed production.

scholarly journals CHARACTERIZATION OF A MALE-STERILE SYSTEM WITH A CLOSELY LINKED SEEDLING MARKER TO FACILITATE F1 HYBRID TOMATO SEED PRODUCTION

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1168e-1168 ◽  
Author(s):  
Edward C. Tigchelaar
Keyword(s):  
Male Sterility ◽  
Seed Production ◽  
Marker Gene ◽  
Hybrid Seed ◽  
Hybrid Seed Production ◽  
Chromosome 2 ◽  
Male Sterile ◽  
Tomato Seed ◽  
F1 Hybrid

The coupling phase linkages have been synthesized between the gene aw (without anthocyanin) and the male sterile gene ms15 (and its alleles ms26, ms47, and an Israeli source of male sterility). Less than 2 map units separate aw and ms15 on chromosome 2, providing a convenient seedling marker gene to rapidly identify male sterility for both inbred development and hybrid seed production. The seedling marker also provides a convenient marker to rapidly assess hybrid seed purity. Unique features of each of the alleles involved in male sterility and their use in inbred and hybrid development will be described.

scholarly journals First Report of Sorghum Ergot Caused by Claviceps africana in the United States

Plant Disease ◽  
1998 ◽  
Vol 82 (5) ◽  
pp. 592-592 ◽  
Author(s):  
T. Isakeit ◽  
G. N. Odvody ◽  
R. A. Shelby
Keyword(s):  
Seed Production ◽  
The United States ◽  
Grain Sorghum ◽  
Hybrid Seed ◽  
High Plains ◽  
Hybrid Seed Production ◽  
Male Sterile ◽  
Production Region ◽  
Corpus Christi ◽  
Chromatography Analysis

In March 1997, ergot was found on sorghum (Sorghum bicolor (L.) Moench) regrowth in several abandoned commercial grain sorghum fields in Cameron and Hidalgo counties in the Lower Rio Grande Valley (LRGV) of Texas. White sphacelia in florets produced honeydew containing macrospores (hyaline, oblong to oval, 10 to 25 μm × 5 to 7 μm) and microspores (hyaline, spherical, 3 μm in diameter). Macrospores germinated iteratively to form secondary conidia when placed on water agar and in situ following rain. Secondary conidia were hyaline, pyriform, with a protruding hilum, and measured 10 to 17 μm × 5 to 7 μm. High-pressure liquid chromatography analysis detected the alkaloid di-hydroergosine in sphacelia, which is unique to C. africana (1). The pathogen was also confirmed on adjacent johnsongrass (S. halepense). The spread of ergot across Texas was associated with the progressive maturation of the commercial sorghum crop as follows: LRGV (mid-May), Coastal Bend near Corpus Christi (June), Winter Garden area southwest of San Antonio (July), and the seed production region of the Texas Panhandle (mid-August). Ergot incidence ranged from a trace to 10% of the heads in (self-fertile) grain sorghum fields of the LRGV. Most heads had only a few infected florets, but a few heads had 35 to 50% of the florets infected. Only trace amounts were found in grain sorghum fields in other areas of the state. Incidence and severity of ergot were greatest in fields of male-sterile sorghums grown for forage. Ergot was generally low in primary heads of male-sterile sorghums in hybrid seed production fields but, in the absence of pollen, axillary tillers sometimes developed high levels of ergot. The major impact of sorghum ergot is expected to be in hybrid seed production fields in the High Plains of Texas. Reference: (1) D. E. Frederickson et al. Mycol. Res. 95:1101, 1991.

SELECTION FOR CROSS-POLLINATION IN BARLEY USING SEGREGATING BULK POPULATIONS

1981 ◽  
Vol 61 (1) ◽  
pp. 17-24 ◽  
Author(s):  
K. W. CAMPBELL ◽  
K. J. KASHA
Keyword(s):  
Seed Production ◽  
Selection Pressure ◽  
Seed Set ◽  
Hybrid Seed Production ◽  
Average Difference ◽  
Male Sterile ◽  
Cross Pollination ◽  
Regular Cycle ◽  
Growth Room ◽  
Selection For

Six bulk populations, each containing a recessive male sterile gene, were used to determine the level of cross-pollination of barley in Ontario for hybrid seed production. Selection pressure for characters that favor cross-pollination was applied by harvesting only male sterile plants to provide seed for the next generation. Seed set on male sterile plants fluctuated greatly from year to year (10.5–51.0%) with no constant trend upward or downward over a 6-yr period from 1968 to 1973. There were no differences in seed set bulk populations grown from remnant seed from previous cycles and from the regular cycle material in 1971 when seed set was low in all populations. However, the same procedure in 1972 provided an average difference of 22.5% in seed set in favor of the advanced selected populations. Cross-pollination was not improved by one cycle of selection under growth room conditions for characters associated with cross-pollination. The influence of a self-pollinated winter increase upon improvement in the level of cross-pollination is discussed. Results indicated that cross-pollination is not sufficient or reliable enough to produce hybrid barley seed in the area tested.

Alfalfa leafcutting bee (Hymenoptera: Megachilidae) pollination of oilseed rape (Brassica napus L.) under isolation tents for hybrid seed production

2001 ◽  
Vol 81 (1) ◽  
pp. 199-204 ◽  
Author(s):  
J. J. Soroka ◽  
D. W. Goerzen ◽  
K. C. Falk ◽  
K. E. Bett
Keyword(s):  
Brassica Napus ◽  
Seed Production ◽  
Oilseed Rape ◽  
Hybrid Seed ◽  
Hybrid Seed Production ◽  
Stocking Rate ◽  
Megachile Rotundata ◽  
Male Sterile ◽  
Brassica Napus L ◽  
Stocking Rates

In this 3-yr field study, the activities of alfalfa leafcutting bees (Megachile rotundata Fabricius) (LCB) at varying stocking levels were monitored in shade cloth isolation tents containing male-sterile and male-fertile rows of oilseed rape Brassica napus L. to determine optimum conditions for hybrid seed production. Bumble bees, Bombus impatiens Cresson, were similarly tested in 1 yr; their pollination activities were minimal, and weight of seed produced on female lines in tents containing bumble bees was similar to that in tents without pollinators. Leafcutting bee activity, as measured by the number of female bees at the entrance to tunnels in the hive, at first increased, then decreased with increasing stocking rate. Duration of time spent visiting flowers did not vary with stocking rate, but was longer on male-fertile than on male-sterile flowers. Production of hybrid seed within tents varied with leafcutting bee stocking rate, with the highest seed yield achieved at stocking rates equivalent to three charges at weekly intervals of 400 000 leafcutting bees per hectare. At optimum LCB stocking rates, the method described provided sufficient seed quantity for small-plot multi-location field evaluation of oilseed rape hybrids. Key words: Megachile rotundata, alfalfa leafcutting bee, Bombus impatiens, Brassica napus, oilseed rape, hybrid seed production, isolation tents

scholarly journals Engineering the AEG1 promoter from cotton to develop male sterile lines

2021 ◽  
Author(s):  
Kamlesh Kumar Soni ◽  
Amita Kush Mehrotra ◽  
Pradeep Kumar Burma
Keyword(s):  
Seed Production ◽  
Reporter Gene ◽  
Tissue Specificity ◽  
Specific Activity ◽  
Open Reading Frame ◽  
Gene Analysis ◽  
Hybrid Seed Production ◽  
Male Sterile ◽  
Reading Frame ◽  
Regulatory Module

This work reports on modifying the Upstream Regulatory Module (URM, 1.5 Kb region upstream of the open reading frame) of Anther Expressing Gene 1 (AEG1) from cotton to achieve anther specific activity. AEG1 was identified in a previous study aimed to isolate a promoter with tapetum specific activity. Such a promoter could then be used to express barnase and barstar genes for developing male sterile and restorer lines for hybrid seed production in cotton. The AEG1 URM was observed to be active in tapetum as well as in roots making it unusable to drive the expression of barnase gene. Analysis of the URM showed the presence of several root specific motifs. Two modified AEG1 URMs were developed, by removing or mutating these motifs and its activity checked in tobacco. The activity of one of the modified URMs, AEG1(DelBmut) was restricted to the anther tissue as observed using the reporter gene beta-glucuronidase. The study also demonstrates that male sterile lines could be developed in tobacco using the AEG1(DelBmut) URM to express the barnase gene. This work thus shows the possibility of engineering promoters to achieve tissue specificity and to develop male sterile lines in cotton.

scholarly journals Identification and Confirmation of RAPD and SCAR Markers Linked to the ms-3 Gene Controlling Male Sterility in Melon (Cucumis melo L.)

2004 ◽  
Vol 129 (6) ◽  
pp. 819-825 ◽  
Author(s):  
Soon O. Park ◽  
Kevin M. Crosby ◽  
Rongfeng Huang ◽  
T. Erik Mirkov
Keyword(s):  
Male Sterility ◽  
Seed Production ◽  
Rapd Markers ◽  
Scar Marker ◽  
Rapd Marker ◽  
Hybrid Seed ◽  
Hybrid Seed Production ◽  
Scar Markers ◽  
Male Sterile ◽  
The Cross

Male sterility is an important trait of melon in F1 hybrid seed production. Molecular markers linked to a male-sterile gene would be useful in transferring male sterility into fertile melon cultivars and breeding lines. However, markers linked to the ms-3 gene for male sterility present in melon have not been reported. Our objectives were to identify randomly amplified polymorphic DNA (RAPD) markers linked to the ms-3 gene controlling male sterility using bulked segregant analysis in an F2 population from the melon cross of line ms-3 (male-sterile) × `TAM Dulce' (male-fertile), convert the most tightly linked RAPD marker to the ms-3 gene into a sequence characterized amplified region (SCAR) marker based on a specific forward and reverse 20-mer primer pair, and confirm the linkage of the RAPD and SCAR markers with the ms-3 gene in an F2 population from the cross of line ms-3 × `Mission' (male-fertile). A single recessive gene controlling male sterility was found in F2 individuals and confirmed in F3 families. Two RAPD markers that displayed an amplified DNA fragment in the male-sterile bulk were detected to be linked to the ms-3 gene in the F2 population from the cross of line ms-3 × `TAM Dulce'. RAPD marker OAM08.650 was closely linked to the ms-3 gene at 2.1 cM. SCAR marker SOAM08.644 was developed on the basis of the specific primer pair designed from the sequence of the RAPD marker OAM08.650. The linked RAPD and SCAR markers were confirmed in the F2 population from the cross of line ms-3 × `Mission' to be consistently linked to the ms-3 gene at 5.2 cM. These markers were also present in 22 heterozygous fertile F1 plants having the ms-3 gene. The RAPD and SCAR markers linked to the ms-3 gene identified, and confirmed here could be utilized for backcrossing of male sterility into elite melon cultivars and lines for use as parents for F1 hybrid seed production.

scholarly journals Blend wheat AL-type hybrid and using SSRs to determine the purity of hybrid seeds

2021 ◽  
Author(s):  
Yingbin Nie ◽  
Dezhen Kong ◽  
Fenjuan Cui ◽  
Wei Sang ◽  
Peiyuan Mu ◽  
...  
Keyword(s):  
Seed Production ◽  
Wheat Yield ◽  
Regression Equation ◽  
Hybrid Seed ◽  
Hybrid Seed Production ◽  
Male Sterile ◽  
Purity Testing ◽  
Hybrid Seeds ◽  
Seed Setting Rate ◽  
Simple Sequence

Heterosis is a promising approach to increase wheat yield from a limited planting area. In this study, a fine quality restorer line 99AR144-1 and three stable male sterile lines, AL18A, AL36A and AL20A, were assigned as male and female, respectively. Seeds of the wheat line 99AR144-1 and three male sterile lines were mixed according to different proportions and then planted at an experimental farm at the Xinjiang Academy of Agri-Reclamation Sciences from 2013 to 2016. When the mixed sowing ratios of combinations 2 (AL36A × 99AR144-1) and 3 (AL20A × 99AR144-1) were 6 to 8%, the seed production yields were higher than the control; the yield of hybrid seed production increased by 98.8 and 19.9%, respectively. This increase was attributed to a rise in the outcrossing seed setting rate. Further, this study used the Xbarc-8 SSR (simple sequence repeat) molecular marker to identify the purity of blend hybrid seeds and establish a regression equation for hybrid seed purity testing. The coefficient of the regression equation were 0.9878 and 0.9689 respectively, which shows that the purity of hybrids can be accurately predicted by using this equation. This method can quickly and accurately identify the seed purity in mixed seed production.

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