Salt stress poses a major challenge to global crop production, especially in cereals, necessitating a comprehensive understanding of salt tolerance mechanisms. Halophytes like Spartina alterniflora, thriving in high-salinity environments, offer valuable insights due to their unique adaptations.

However, the molecular mechanisms behind their salt tolerance remain largely unexplored. Addressing these knowledge gaps is crucial for developing strategies to enhance crop resilience. Due to these challenges, there is a need for in-depth research to elucidate the genetic and molecular basis of salt tolerance in halophytes.

A collaborative research team from the Chinese Academy of Agricultural Sciences has made significant strides in this area, with their findings published in the journal Horticulture Research on March 28, 2024. The study employs machine learning to investigate the transcriptomic responses of Spartina alterniflora to various salt concentrations, revealing new insights into its salt tolerance mechanisms.

The study on Spartina alterniflora revealed significant transcriptional changes in response to salt stress, affecting key pathways such as gene transcription, ion transport, and reactive oxygen species metabolism.

A notable discovery was the identification of a SWEET gene family member, SA_12G129900.m1, which showed convergent selection with its rice ortholog, SWEET15. This gene is crucial for salt tolerance, suggesting its potential for genetic engineering to improve crop resilience.

The study also conducted genome-wide analyses of alternative splicing responses to salt stress, highlighting the complex interplay between transcriptional regulation and post-transcriptional modifications. Interestingly, there was minimal overlap between differentially expressed and differentially spliced genes, indicating distinct regulatory mechanisms.

This innovative approach, combining machine learning with transcriptomic analysis, provides a deeper understanding of salt tolerance mechanisms and offers valuable genetic resources for developing salt-tolerant crops.

Dr. Huihui Li, the corresponding author, stated, “Our innovative approach combining machine learning with transcriptomic analysis offers new insights into the salt tolerance mechanisms of Spartina alterniflora. This research not only enhances our understanding of halophyte biology but also provides valuable genetic resources for improving crop resilience in saline conditions.”

The findings from this study have significant implications for agricultural biotechnology. By identifying key genes and pathways involved in salt tolerance, researchers can develop genetically engineered crops with enhanced resilience to salt stress. This could lead to improved crop yields in saline environments, contributing to global food security in the face of climate change and soil salinization.

Researchers have developed a lightweight fluidic engine to power muscle-mimicking soft robots for use in assistive devices. What sets the new engine apart is its ability to generate significant force without being tethered to an external power source.

“Soft robots that are powered by fluid engines—such as hydraulic or pneumatic action—can be used to mimic the behavior of muscle in ways that rigid robots cannot,” says Hao Su, corresponding author of a paper on the work and an associate professor of mechanical and aerospace engineering at North Carolina State University.

“This makes these robots particularly attractive for use in assistive devices that improve people’s ability to move their upper or lower limbs.”

However, most fluid engines are physically connected to an external power source, such as a large air compressor. That significantly limits their utility. And previous fluid engines that were not tethered to external power sources were not able to generate much force, which also limited their utility.

“Our work here addresses both of those challenges,” Su says. “Our fluidic engine is not tethered to an external source but can still generate up to 580 Newtons of force.”

The new engine works by pumping oil into and out of a chamber in a soft robot, causing the soft robot to act as an artificial muscle that is flexing and relaxing. The fluidic engine’s pump is driven by a battery-powered high-torque motor that allows it to generate significant pressure, enabling the artificial muscle to exert significant force.

In proof-of-concept testing, the researchers not only assessed the amount of force the new engine can generate, but how efficiently the engine converts electrical power into fluidic power.

“We found that we were able to generate an unprecedented amount of force for an untethered engine, while still keeping the weight of the fluidic engine low,” says Antonio Di Lallo, first author of the paper and a postdoctoral researcher at NC State.

“And the maximum efficiency of our fluidic engine is higher than previous portable, untethered engines.”

The paper, “Untethered Fluidic Engine for High-Force Soft Wearable Robots,” is published open access in the journal Advanced Intelligent Systems.

Climatic stability over millions of years has allowed ancient and isolated freshwater fishes to flourish in areas such as the 356,000 square kilometers from Shark Bay to Esperance in southwest Western Australia.

But now accelerating climate changes threaten this biodiversity hotspot and its native fish species, according to new research in journal Heredity led by Matthew Flinders Professor Luciano Beheregaray and Ph.D. Sean Buckley.

Made up of temperate forests and grasslands, the corner of the continent hosts more than 8,000 species of plants, of which about half are endemic, and more than 500 recorded vertebrate species.

Unfortunately, the southwest section of WA is also a climate change hotspot as hotter, drier conditions take hold, a journal summary explains.

Since the 1970s, rainfall has decreased by 10–15% and is predicted to worsen in the coming decades. Over the last century, the region has also experienced a 1.1°C increase in temperature.

“This remarkable biodiversity is already suffering the consequences, including species declines and recent forest die-offs,” says Flinders University Molecular Ecology Lab researcher Dr. Buckley, now Lecturer in Molecular Ecology and Environmental Management at Edith Cowan University, WA.

“This is especially concerning if historically stable climates have been key to generating this biodiversity: climate change presents a novel threat to this incredible ecosystem, and endemic species might not have evolved the capacity to respond.

“Understanding the role of historical climate stability is required to better predict the potential impacts of climate change in the region.”

The research focused on two small freshwater fishes endemic to the region: the western (Nannoperca vittata) and little (Nannoperca pygmaea) pygmy perches.

The western pygmy perch is found across the region, while the little pygmy perch is only found in a handful of rivers (and is listed as Endangered in state, national and global conservation lists).

“Based on our prior research, we knew that these species had likely existed in the landscape for a very long time and would be ideal models to look at the interaction of climatic history and evolutionary patterns,” says Professor Beheregaray.

The Molecular Ecology Lab study generated genomic data from nine populations accessed through museum collections, assessing their evolutionary relationships, divergence histories, and gene flow over time.

He says, “We combined these methods with environmental approaches—specifically, species distribution modeling—to see how the climatic history of the region had shaped their evolution.

“Using a time calibration derived from previous studies, we found that these two cryptic species last shared an ancestor around nine million years ago, with no evidence for gene flow between them. This suggests that they have been persisting in isolation for a very long time.”

The environmental approaches supported this conclusion.

Using reconstructions of past climate in the region, the study found relatively little change in species ranges over time: save for a small expansion coastward during the lower sea levels of ice ages, pygmy perches have been found in the same areas since the Pliocene.

“These patterns reflect the climate itself, which has remained relatively stable over that same time period, particularly compared to other parts of Australia,” adds Dr. Buckley.

“However, modeling these distributions under future climate change produced a stark picture, with large declines in range across the species. In a business-as-usual scenario, this included the complete loss of suitable climate for one of the cryptic species within the next few decades.”

Conservation management actions which improve adaptive capacity, like genetic rescue, might be necessary to preserve the unique diversity of this part of WA.

Other ambitious strategies, like captive-breeding and reintroductions programs have been successful for other threatened pygmy perches, and may be necessary in the future, researchers say.