AN UNUSUAL HETEROMORPHIC INCOMPATIBILITY SYSTEM. DISTYLY, SELF-INCOMPATIBILITY, POLLEN LOAD AND FECUNDITY IN ANCHUSA OFFICINALIS (BORAGINACEAE)

Stigmatic pollen loads were analyzed from naturally pollinated pin and thrum form flowers of Amsinckia douglasiana and A. vernicosa var. furcata. Pin stigmas captured more total pollen than thrum stigmas. Pins experienced either net self-pollination or random pollination. Thrum stigmas experienced significant disassortative pollination. Comparing pollen loads from intact and emasculated thrum flowers of A. douglasiana indicated that self-pollination and geitonogamy were relatively unimportant in the pollination of the thrum form. The level of disassortative pollination of A. vernicosa var. furcata does not appear to be high enough to account for the level of disassortative mating observed by progeny testing, suggesting that this species may possess an incomplete stylar self-incompatibility system such as has been reported in A. grandiflora.

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The formation of the tryphine coating the pollen grains of Raphanus , and its properties relating to the self-incompatibility system

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1973.0040 ◽

1973 ◽

Vol 184 (1075) ◽

pp. 149-165 ◽

Cited By ~ 95

Keyword(s):

Granular Material ◽

Pollen Grains ◽

The Self ◽

Self Incompatibility ◽

Pollen Maturation ◽

Incompatible Pollen ◽

Incompatibility System ◽

Two Stages ◽

Stimulation Of ◽

Incompatible Pollen Tube

The tryphine that coats the pollen grains of Raphanus is tapetally synthesized and is composed of a fibro-granular and a lipidic component. The fibro-granular material is proteinaceous and is secreted by cisternae of the endoplasmic reticulum. The lipidic component is derived, mainly, from degraded elaioplasts. The fibro-granular material is applied to the pollen exine first, followed by the lipidic mass. The tryphine condenses during the final stages of pollen maturation and dries down to form a thick, highly viscous coating. The major part of the condensation appears to result from dehydration. The tryphine, extracted from the pollen by a centrifugal method and mounted in a membrane, appears to be capable of penetrating the outer layers of a stigma of the same species and, if the pollen from which it was derived is incompatible with respect to the stigma, the stimulation of the production of the callosic reaction body in a manner similar to an incompatible pollen tube. It is proposed that, in Raphanus , substances responsible for the initiation of at least two stages in the self-incompatibility system are held in the tryphine.

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Expression of Brassica napus GLO1 is sufficient to breakdown artificial self-incompatibility in Arabidopsis thaliana

10.1101/2020.04.27.064394 ◽

2020 ◽

Author(s):

Patrick Kenney ◽

Subramanian Sankaranarayanan ◽

Michael Balogh ◽

Emily Indriolo

Keyword(s):

Arabidopsis Thaliana ◽

Brassica Napus ◽

Specific Interaction ◽

Peptide Ligand ◽

Self Incompatibility ◽

Stigma Surface ◽

Compatibility Factor ◽

Incompatibility System ◽

Allele Specific ◽

Armadillo Repeat

AbstractMembers of the Brassicaceae family have the ability to regulate pollination events occurring on the stigma surface. In Brassica species, self-pollination leads to an allele specific interaction between the pollen small cysteine-rich peptide ligand (SCR/SP11) and the stigmatic S-receptor kinase (SRK) that activates the E3 ubiquitin ligase ARC1 (Armadillo repeat-containing 1), resulting in proteasomal degradation of various compatibility factors including Glyoxalase I (GLO1) which is necessary for successful pollination. Suppression of GLO1 was sufficient to reduce compatibility, and overexpression of GLO1 in self-incompatible Brassica napus stigmas resulted in partial breakdown of the self-incompatibility response. Here, we verified if BnGLO1 could function as a compatibility factor in the artificial self-incompatibility system of Arabidopsis thaliana expressing AlSCRb, AlSRKb and AlARC1 proteins from A. lyrata. Overexpression of BnGLO1 is sufficient to breakdown self-incompatibility response in A. thaliana stigmas, suggesting that GLO1 functions as an inter-species compatibility factor. Therefore, GLO1 has an indisputable role as a compatibility factor in the stigma in regulating pollen attachment and pollen tube growth. Lastly, this study demonstrates the usefulness of an artificial self-incompatibility system in A. thaliana for interspecific self-incompatibility studies.

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Inferences on specificity recognition at the Malus×domestica gametophytic self-incompatibility system

Scientific Reports ◽

10.1038/s41598-018-19820-1 ◽

2018 ◽

Vol 8 (1) ◽

Cited By ~ 8

Author(s):

Maria I. Pratas ◽

Bruno Aguiar ◽

Jorge Vieira ◽

Vanessa Nunes ◽

Vanessa Teixeira ◽

...

Keyword(s):

Malus Domestica ◽

Self Incompatibility ◽

Incompatibility System

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Breeding System, Karyotype and Variation Within and Between Populations of Rutidosis leptorrhynchoides F Muell (Asteraceae, Inuleae)

Australian Journal of Botany ◽

10.1071/bt9910085 ◽

1991 ◽

Vol 39 (1) ◽

pp. 85 ◽

Cited By ~ 2

Author(s):

P Leeton ◽

YJ Fripp

Keyword(s):

Chromosome Number ◽

Breeding System ◽

Geographic Distance ◽

Endangered Plant ◽

Allozyme Analysis ◽

Self Incompatibility ◽

Eastern Australia ◽

Incompatibility System ◽

Leaf Dimensions ◽

Allozyme Loci

The endangered plant species, Rutidosis leptorrhynchoides (button wrinklewort), is now known from only a few populations in each of two regions separated by approximately 500 km in south-eastern Australia. Plants were examined from several populations from each region. No differences in chromosome number or morphology were observed among plants or populations. All counts were diploid, 2n = 26. Viable progeny were obtained following self-pollination and allozyme analysis indicated that these progeny were the result of selfing and not agamospermy. This species is not an obligate outcrosser and does not have a classical pre-zygotic self-incompatibility system. However, outcross pollen may have an advantage over self pollen and this species may thus be preferentially outcrossing. The pollen: ovule ratios (mean 3186 ± 48.5) were consistent with this hypothesis. Allele frequencies at allozyme loci diferred little between populations, with an estimated 97% of the variation within populations. There was no correlation between genetic distance and geographic distance. In contrast, for the leaf dimensions of plants germinated and raised together in a glasshouse there were differences between plants from the two regions. It is recommended that populations from both regions should be conserved.

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