Entries by Philip Carella

PEN3 and PDR12 secrete camalexin to the apoplast to limit pathogen growth in Arabidopsis (Plant Cell)

Phytoalexins are important antimicrobial compounds that plants synthesize to fend off invading pathogens. In the Brassica family, the tryptophan (trp)-derived phytoalexin ‘camalexin’ provides broad-spectrum resistance against bacterial, fungal, and oomycete pathogens. The regulation of camalexin biosynthesis during pathogen attack is well described, however a mechanistic understanding of its transport towards invading pathogens was previously unresolved. […]

Pipecolic contributes to systemic acquired resistance in barley ($) (MPMI)

Systemic acquired resistance (SAR) is a robust long-distance immune response mediated by a diverse contingent of candidate phloem-mobile signals that prime distal uninfected tissues for enhanced resistance to future infections. The lysine-derived catabolite pipecolic acid (Pip) has emerged as a key mediator of SAR in dicot model species like Arabidopsis, however comparatively less is known […]

A simple arsenic detoxification strategy in the fern Pteris vittata ($) (Curr Biol)

Arsenic contamination is a growing human health threat. The fern Pteris vittata demonstrates a remarkable capacity to accumulate and sequester high levels of the toxic heavy metal arsenic from contaminated environments. Cai et al. used an ‘omics’-guided approach to identify and characterize the molecular mechanisms that afford arsenic tolerance in Pteris. De novo transcriptome analysis […]

The macroevolutionary history of light signaling ($) (Mol Plant)

The ability to sense and respond to light is a fundamental feature of photosynthetic organisms like plants. Much has been learned about the molecular genetic mechanisms controlling light perception and downstream signaling processes in evolutionarily young land plant lineages like angiosperms, with comparatively less knowledge in early divergent plants (bryophytes, lycophytes) or their algal predecessors. […]

Land plants recruited an ancestral bHLH for tip-growing surface cell development ($) (New Phytol)

Land plants (embryophytes) evolved from freshwater charophycean algae over 450 million years ago. The transition from aquatic to terrestrial environments likely required the evolution and expansion of genetic programs controlling three dimensional growth and the formation of tip-growing surface cells (rhizoids/root hairs) from the plant body. Bonnot et al. investigated the function and evolutionary history […]

Antagonistic responses to ‘symbiotic’ AM fungi in the non-host Arabidopsis thaliana ($) (New Phytol)

A strikingly vast array of phylogenetically distant plants are able to form intimate interactions with symbiotic arbuscular mycorrhizal (AM) fungi for the mutually beneficial exchange of nutrients. Several years of intensive research have revealed the complex regulatory networks and genetic ‘toolkits’ that enable these interactions, yet comparatively less attention is paid to understanding interactions between […]

Leaf age dictates abiotic versus biotic stress signalling in Arabidopsis (PNAS)

Plants sense and respond to various external stimuli throughout their lifespan. During stress responses brought forth by abiotic or biotic factors, molecular and physiological adjustments mediated by distinct yet interconnected hormone pathways play critical roles in plant survival. Berens et al. investigate how leaves of the Arabidopsis rosette prioritize stress signalling outputs during combined or […]

A smut fungus of Brassicaceae plants uses conserved and unique strategies to manipulate perennial hosts ($) New Phytol.

Biotrophic phytopathogens manipulate living hosts for the procurement of nutrients essential for growth and reproduction. It is therefore critical for invading biotrophs to evade or suppress immune responses without impacting overall plant function. In a recent study published in New Phytologist (2019), Courville et al. resolve the genomic and transcriptomic signatures of the smut fungus […]

A key role for flavanols in the promotion of pollen success (PNAS) ($)

The reproductive success of angiosperms relies on the fertilization of the female gametophyte (egg sac) by pollen that travels long-distances in the pistil. Previous studies suggest a role for phenylpropanoid-related metabolites (flavonoids and anthocyanins) in controlling pollen growth and fertilization, however a mechanistic understanding of their function during this critical developmental process remains unknown. In […]