Heat stress induces ferroptosis-like cell death in plants.

In plants, regulated cell death (RCD) plays critical roles during development and is essential for plant-specific responses to abiotic and biotic stresses. Ferroptosis is an iron-dependent, oxidative, nonapoptotic form of cell death recently described in animal cells. In animal cells, this process can be triggered by depletion of glutathione (GSH) and accumulation of lipid reactive oxygen species (ROS).

In vitro inhibition of incompatible pollen tubes in Nicotiana alata involves the uncoupling of the F-actin cytoskeleton and the endomembrane trafficking system.

In the S-RNase-based self-incompatibility system, subcellular events occurring in the apical region of incompatible pollen tubes during the pollen rejection process are poorly understood. F-actin dynamics and endomembrane trafficking are crucial for polar growth, which is temporally and spatially controlled in the tip region of pollen tubes. Thus, we developed a simple in vitro assay to study the changes in the F-actin cytoskeleton and the endomembrane system at the apical region of incompatible pollen tubes in Nicotiana alata.

NnSR1, a class III non-S-RNase constitutively expressed in styles, is induced in roots and stems under phosphate deficiency in Nicotiana alata.

Background And Aims: Non-S-ribonucleases (non-S-RNases) are class III T2 RNases constitutively expressed in styles of species with S-RNase-based self-incompatibility. So far, no function has been attributed to these RNases. The aim of this work is to examine if NnSR1, a non-S-RNase from Nicotiana alata, is induced under conditions of phosphate (Pi) deprivation.

Early F-actin disorganization may be signaling vacuole disruption in incompatible pollen tubes of Nicotiana alata.

Self-incompatibility (SI) systems appeared early in plant evolution as an effective mechanism to promote outcrossing and avoid inbreeding depression. These systems prevent self-fertilization by the recognition and rejection of self-pollen and pollen from closely related individuals. The most widespread SI system is based on the action of a pistil ribonuclease, the S-RNase, which recognizes and rejects incompatible pollen.

Disorganization of F-actin cytoskeleton precedes vacuolar disruption in pollen tubes during the in vivo self-incompatibility response in Nicotiana alata.

Background And Aims: The integrity of actin filaments (F-actin) is essential for pollen-tube growth. In S-RNase-based self-incompatibility (SI), incompatible pollen tubes are inhibited in the style. Consequently, research efforts have focused on the alterations of pollen F-actin cytoskeleton during the SI response.

Molecular and genetic characterization of novel S-RNases from a natural population of Nicotiana alata.

Self-incompatibility in the Solanaceae is mediated by S-RNase alleles expressed in the style, which confer specificity for pollen recognition. Nicotiana alata has been successfully used as an experimental model to elucidate cellular and molecular aspects of S-RNase-based self-incompatibility in Solanaceae. However, S-RNase alleles of this species have not been surveyed from natural populations and consequently the S-haplotype diversity is poorly known.