Antarctic fungi found to be effective against citrus canker

Citrus canker is a disease that affects all citrus species and varieties. It is caused by Xanthomonas citri, a bacterium originally from Asia, where it is endemic in all citrus-producing countries. Although the bacterium can be combated in several ways, none is sufficient to eradicate the disease. Therefore, new chemical or biological methods of protecting citrus groves have to be pursued.

In an article published in Letters in Applied Microbiology, a team led by Daiane Cristina Sass, Lara Durães Sette and Henrique Ferreira, professors in São Paulo State University’s Bioscience Institute (IB-UNESP) in Rio Claro, Brazil, identify 29 fungi with proven action against X. citri. The origin of the fungi is surprising. They were isolated from samples of soil and marine sediment collected in Antarctica. read more…

Terrestrial and marine Antarctic fungi extracts active against Xanthomonas citri subsp. citri
Biotechnological potential of secondary metabolites from Antarctica fungi with activity against plant pathogenic bacteria

An orchid matches its scent rhythm to the locals

Interesting, white flowers are white to attract pollinators at night, several orchids I’ve owned have a scent that is very strong after dark but barely there during the day.

We find that the floral scent of the orchid Gymnadenia conopsea differs between day and night, and the increase in scent from day to night is stronger in populations with nocturnal pollination. This is the first study to report genetic variation in floral scent emission rhythms within the same species, and this is an important first step to understand the evolution of floral scent.

read more…

Diel pattern of floral scent emission matches the relative importance of diurnal and nocturnal pollinators in populations of Gymnadenia conopsea

Echinacea purpurea aka Purple Coneflower

Perennial, loves sun, doesn’t mind occasional dry spells, benefits from dead heading and dividing clumps every 3 years or so.

Native to North America, there are about 9 species in this genus. It’s been a garden favorite as far back as the early 1900s where it is often referred to as the ‘dull pink coneflower’

It is a strongly recommended addition to bee and butterfly gardens and said to be deer resistant

Yes, some plants do use camouflage


…. But a review by scientists from the University of Exeter and the Kunming Institute of Botany (Chinese Academy of Sciences) found plants use a host of techniques long known to be used by animals.

These include blending with the background, “disruptive colouration” (using high-contrast markings to break up the perceived shape of an object) and “masquerade” (looking like an unimportant object predators might ignore, such as a stone).

“It is clear that plants do more than entice pollinators and photosynthesise with their colours—they hide in plain sight from enemies too,” said Professor Martin Stevens, of the Centre for Ecology and Conservation on Exeter’s Penryn Campus in Cornwall.

“From ‘decoration’, where they accumulate things like dust or sand on their surface, to disruptive coloration, they use many of the same methods as animals to camouflage themselves.

“We now need to discover just how important a role camouflage has in the ecology and evolution of plants.”

read more….

Exeter Press Release

Plants gain and ditch the ability to fix nitrogen

Plants, like all living things, need nitrogen to build amino acids and other essential biomolecules. Although nitrogen is the most abundant element in air, the molecular form of nitrogen found there is largely unreactive. To become useful to plants, that nitrogen must first be “fixed,” or busted out of its molecular form and linked with hydrogen to make ammonia. The plants can then get at it by catalyzing reactions with ammonia.

But plants can’t fix nitrogen. Bacteria can.

Some legumes and a few other plants have a symbiotic relationship with certain bacterial species. The plants build specialized structures on their roots called nodules to house and feed the bacteria, which in turn fix nitrogen for the plants and assure them a steady supply of ammonia. Only 10 families of plants have the ability to do this, and even within these families, most genera opt out. Ever since the symbiosis was discovered in 1888, plant geneticists have wondered: why? If you could ensure a steady supply of nitrogen for use, why wouldn’t you? Plants repeatedly got rid of their ability to obtain their own nitrogen

Phylogenomics reveals multiple losses of nitrogen-fixing root nodule symbiosis $$$

Rudbeckia hirta aka Black Eyed Susan

Not surprisingly this is in the sunflower branch of the family tree and North American native.

It loves lots of sun, tolerate occasional dry spells and are easily grown from seed or pick up a flat of the plants and plant them.

They are perennials, divide them every few years to keep them flowering.

Dead heading the plants ( cut off spent flowers before they go to seed ) will prolong the blooming cycle.

Used in traditional medicine, not all the parts are edible. ( Don’t try it at home ) There are many references to it as a kitchen garden plant as far back as the early 1800s. The older mentions all reference the orange center, not all the newer varieties still have the orange center.

Plants pass climate data onto children

Plants integrate seasonal signals, including temperature and day length, to optimize the timing of developmental transitions. Seasonal sensing requires the activity of two proteins, FLOWERING LOCUS C (FLC) and FLOWERING LOCUS T (FT), that control certain developmental transitions in plants. During reproductive development, the mother plant uses FLC and FT to modulate progeny seed dormancy in response to temperature. We found that for regulation of seed dormancy, FLC and FT function in opposite configuration to how those same genes control time to flowering. For seed dormancy, FT regulates seed dormancy through FLC gene expression and regulates chromatin state by activating antisense FLC transcription. Thus, in Arabidopsis the same genes controlled in opposite format regulate flowering time and seed dormancy in response to the temperature changes that characterize seasons. paper $$

Mother knows best — how plants help offspring by passing on seasonal clues

FLOWERING LOCUS C (FLC) regulates development pathways throughout the life cycle of Arabidopsis