Tagged: programmed cell death

Mitochondria and stress signalling

How does a plant sense stress and pass those signals around its body? Corentin Dourmap and colleagues have reviewed the role of mitochondria in the plant cell and how they interact with stress signalling. The mitochondria are power generators of the cell that keep the cell running. They found throughout the plant. Their role and ubiquity makes them a key element of understanding plant stress, Dourmap and colleagues write. “Given their strong involvement in energy homeostasis, mitochondria are key organelles for plant responses to environmental stresses. Moreover, they function through an important surface of contact and strong biochemical exchanges with...

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A window in Aponogeton madagascariensis.

Opening a window on plant cell death

Let me introduce you to the wonderful world of the lace plant, Aponogeton madagascariensis. This exotic species native to streams in Madagascar has travelled far to become the focus of the lab of Prof Arunika Gunawardena at the University of Dalhousie in Halifax Nova Scotia. I was fortunate this week to be invited as external examiner for one of Arunika’s PhD students Gaolathe Rantong who gave a beautiful presentation on this fascinating plant. The lace plant is aptly named as its mature leaves form a delicate lattice of perforations (see right) and Arunika’s lab has been asking how these holes...

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Tapetum and middle layer control of male fertility in kiwifruit

Tapetum and middle layer control of male fertility in kiwifruit

Kiwifruit (Actinidia deliciosa) male-sterile anthers abort at the microspore-stage, but the role sporophytic tissues in controlling male-sterility is unknown. Falasca et al. show that the tapetum and middle-layer exhibit secretory activity and degenerate by programmed cell death (PCD), but PCD is later in male-sterile than in male-fertile anthers. Calcium accumulates in cell walls of the middle layer and tapetum and in the exine of microspores and pollen, reaching higher levels in male-sterile anthers. They conclude that male sterility in kiwifruit is induced by anther wall tissues through prolonged secretory activity caused by a delay in PCD, in the middle layer...

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Mastoparan-induced programmed cell death in Chlamydomonas

Mastoparan-induced programmed cell death in Chlamydomonas

Under stress-promoting conditions unicellular algae can undergo programmed cell death (PCD), but the mechanisms are poorly understood. Yordanova et al. expose Chlamydomonas reinhardtii to the G-protein activator mastoparan (MP) and find that cells express several features of necrosis and vacuolar cell death, accompanied by nuclear condensation and DNA fragmentation. Depending on the physiological state of the cells and their sensitivity to MP, a portion of cells undergo early PCD through a process not mediated by capase, whereas other cells die at a slower pace that involves capase-like pathways. The findings thus reveal novel elements of the cell death process in algae...

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