Plants smell growth rates of other plants and adopt their own growth

Amazing stuff!

"All plants constantly release volatile organic compounds, or VOCs, into the air ... But a new study suggests that healthy plants may also be sniffing out the competition.

Researchers tested three barley varieties with different growth speeds: a slower-growing cultivar ... an intermediate grower ... and a fast-growing one named ... Over 25 days, the team exposed plants to each other’s VOCs and tracked both physical growth and changes in gene activity.

Based on the type of airborne chemicals released by the specimens nearby, the plants grew more or less aggressively. Barley exposed to scents from fast growers bulked up their biomass, while plants surrounded by slower-growing neighbors dialed themselves back too. Being around slower growers boosted stress response pathways, while fast-growing neighbors triggered genes involved in cell growth and DNA replication. ..."

From the abstract:

"Plants continuously emit volatile organic compounds (VOCs), which can influence the physiology and behavior of neighboring plants. While the ecological role of stress-induced VOCs is well established, the function of constitutive VOCs released by undamaged plants in mediating plant-plant interactions remains less understood.

Here, we demonstrate that barley plants can detect the growth rate of undamaged conspecific neighbors through constitutive VOCs and respond by modulating their growth-defense trade-off accordingly.

Exposure to volatiles from cultivars with contrasting growth (slow or fast) triggered distinct shifts in biomass accumulation and gene expression in receiver plants, whereas VOCs from cultivars with similar growth rates had negligible effects.

Transcriptomic analysis revealed cultivar-specific transcriptional reprogramming of growth- and defense-related pathways, suggesting that constitutive VOCs convey information about emitter identity and competitive vigour that receiver plants use to adaptively reallocate resources and prime stress responses in anticipation of competition. These findings uncover a previously unrecognized role of constitutive VOCs as reliable cues of emitter identity and vigor, mediating adaptive responses in neighboring plants under competitive scenarios."

ScienceAdviser

Plants select growth strategies by spying on their neighbors’ scents

Volatiles released by undamaged plants mediate the adaptive growth strategies in neighbors (open access)

Scientists Create First-Ever map of smell receptors in the nose

Amazing stuff!

"At a glance

• Scientists have created the first detailed map of smell receptors in the nose, catching up with similar achievements in sight, hearing, and touch.
• The map reveals that smell receptors are highly organized into tight bands based on type.
• The findings provide foundational knowledge needed to develop better therapies for loss of smell.

...

Yet from a scientific perspective, “olfaction is super-mysterious,” ... with basic biological understanding lagging behind that of vision, hearing, and touch. ...

Working in mice, ... team have now created the first detailed map of how the thousand-plus types of smell receptors in the nose are organized.

They discovered that unlike what scientists had long believed, the neurons expressing these receptors have a high degree of spatial organization: They form horizontal stripes based on receptor type from the top of the nose to the bottom. ..."

From the highlights and abstract:

"Highlights

• ∼1,100 olfactory receptors adopt stereotyped spatial distributions in the epithelium

• Epithelial space coherently regulates the graded expression of ∼250 genes

• Precursor spatial identities bias olfactory receptor choice

• Receptor positions in the nose are aligned with their axonal targets in the brain

Summary

Although topographical maps organize many peripheral sensory systems, mouse olfactory sensory neurons (OSNs) are thought to randomly choose which one of ∼1,100 possible olfactory receptors (ORs) to express, with spatial organization in the olfactory epithelium limited to a handful of broad anatomical “zones” that modestly restrict OR choice.

Here, we reveal that each OR is instead expressed at a unique mean dorsoventral position, thereby instantiating a stereotyped receptor map in the olfactory epithelium.

OSN dorsoventral identities are encoded by a coherent gene expression program, which includes key transcription factors and axon guidance molecules; use of this program reflects a dorsoventral gradient in retinoic acid signaling, translates each physical location into a spatially appropriate distribution of potential OR choices, and aligns receptor maps in the nose and brain.

Spatial order in the olfactory system, therefore, arises from a continuously varying transcriptional code that precisely organizes the many discrete channels responsible for smell."

Scientists Create First-Ever ‘Smell Map’ | Harvard Medical School "A detailed diagram of smell receptors in the nose fills in missing details of how olfaction works"

A spatial code governs olfactory receptor choice and aligns sensory maps in the nose and brain (open access)

Graphical abstract

Figure 2 Each OSN subtype occupies a unique region of the epithelium

A pilgrimage to the corpse flower in Sydney

A rare moment for our noses to behold! Or fragrance is in the nose of the nose of the beholder! 😊

"With bated breath—and plugged noses—spectators are waiting for the rare blossoming of a giant, rancid flower in Sydney. 

The endangered corpse flower, lovingly named “Putricia,” is poised to bloom for just 24 hours at the Royal Botanic Gardens of Sydney—the first blossom in 15 years. And the plant has gained a cult following, despite the fact that its aroma has been likened to “wet socks, hot cat food, or rotting possum flesh.” 

Thousands of viewers have tuned in to the Gardens’ livestream, though there’s not much to see yet: “Putricia stands silent and tall in front of a brown curtain, comfortably ensconced behind a red velvet rope,”"

Global Health NOW: 012325

Corpse Flower: A Plant to Die For "A Corpse Flower — Bunga Bangkai — is about to bloom in Sydney for the first time in fifteen years."