Dear Editor,In most flowering plants, the stigma of the flower represents the barrier that prevents any unrelated or incompatible （genetically similar） pollen from germination and fertilizing the ovule, leading to e...Dear Editor,In most flowering plants, the stigma of the flower represents the barrier that prevents any unrelated or incompatible （genetically similar） pollen from germination and fertilizing the ovule, leading to either defective or genetically unfavorable embryos. In Brassicaceae, self-incompatibility （SI） is a genetic mechanism in the stigmas that can discern compatible versus incompatible mate （pollen）, in turn, rejecting self or incompatible pollen, while allowing non-self or compatible pollen to develop successfully to fertilize the ovules. Thus, stigmas have evolved complex mechanisms and specialized proteins to reject incompatible mates and to recognize and accept compatible pollen （Doucet et al., 2016）. The fact that SI has been shown to exclusively operate in the stigmas temporally before and during anthesis （Kandasamy et al., 1993） indicates that multiple metabolic pathways essential for pollination exist in these stigmatic papillary cells.展开更多
Dear Editor, Self-incompatibility （SI） is a genetic mechanism through which flowering plants prevent self-pollination to ensure out- crossing and genetic diversity. In Brassica sp., this mechanism is controlled by ...Dear Editor, Self-incompatibility （SI） is a genetic mechanism through which flowering plants prevent self-pollination to ensure out- crossing and genetic diversity. In Brassica sp., this mechanism is controlled by the self-incompatibility （S） locus, in which, the stigmatic ＇S-locus receptor kinase （SRK）＇ recognizes the ＇S-locus cysteine rich protein （SCR）＇ from the self-pollen to elicit an active rejection response. This results in blocking of compatibil- ity factors from being delivered to the site of pollen attachment leading to self-pollen rejection （Chapman and Goring, 2010）. In contrast, following recognition of compatible signals from the cross-pollen or compatible pollen （CP）, the stigma releases its resources such as water and nutrients to the dry pollen so that the pollen tube can germinate and penetrate the stigmatic cuticle leading to successful fertilization. Thus, an incompatible or self-pollen is fully capable of eliciting a compatible response, but is actively rejected before compatible responses can occur.展开更多
文摘Dear Editor,In most flowering plants, the stigma of the flower represents the barrier that prevents any unrelated or incompatible （genetically similar） pollen from germination and fertilizing the ovule, leading to either defective or genetically unfavorable embryos. In Brassicaceae, self-incompatibility （SI） is a genetic mechanism in the stigmas that can discern compatible versus incompatible mate （pollen）, in turn, rejecting self or incompatible pollen, while allowing non-self or compatible pollen to develop successfully to fertilize the ovules. Thus, stigmas have evolved complex mechanisms and specialized proteins to reject incompatible mates and to recognize and accept compatible pollen （Doucet et al., 2016）. The fact that SI has been shown to exclusively operate in the stigmas temporally before and during anthesis （Kandasamy et al., 1993） indicates that multiple metabolic pathways essential for pollination exist in these stigmatic papillary cells.
文摘Dear Editor, Self-incompatibility （SI） is a genetic mechanism through which flowering plants prevent self-pollination to ensure out- crossing and genetic diversity. In Brassica sp., this mechanism is controlled by the self-incompatibility （S） locus, in which, the stigmatic ＇S-locus receptor kinase （SRK）＇ recognizes the ＇S-locus cysteine rich protein （SCR）＇ from the self-pollen to elicit an active rejection response. This results in blocking of compatibil- ity factors from being delivered to the site of pollen attachment leading to self-pollen rejection （Chapman and Goring, 2010）. In contrast, following recognition of compatible signals from the cross-pollen or compatible pollen （CP）, the stigma releases its resources such as water and nutrients to the dry pollen so that the pollen tube can germinate and penetrate the stigmatic cuticle leading to successful fertilization. Thus, an incompatible or self-pollen is fully capable of eliciting a compatible response, but is actively rejected before compatible responses can occur.
