Scare your plants to produce stronger offspring


UNIVERSITY PARK, Pa. — By temporarily silencing the expression of a critical gene, researchers fooled soybean plants into sensing they were under siege, encountering a wide range of stresses. Then, after selectively cross breeding those plants with the original stock, the progeny “remember” the stress-induced responses to become more vigorous, resilient and productive plants, according to a team of researchers.

This epigenetic reprogramming of soybean plants, the culmination of a decade-long study, was accomplished not by introducing any new genes but by changing how existing genes are expressed. That is important because it portends how crop yields and tolerance for conditions such as drought and extreme heat will be enhanced in the future, according to lead researcher Sally Mackenzie, professor in the departments of Biology and Plant Science at Penn State.

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Species, Variety, Cultivar

Groups

  • Angiosperms: Flowering plants
  • Gymnosperms: Conifers, cycads, allies
  • Pteridophytes: Ferns
  • Bryophytes: Mosses and liverworts
  • Families:

  • Currently 642 families
  • Genus:

  • Currently 17,020
  • Group of related plants
  • Origin, type, group
  • Species:

  • Genus name + specific feature that makes it different than other plants in Genus
  • Breeds true from seeds or cloning
  • The largest group in which two parents can create fertile offspring
  • Variety:

  • Usually occurs in nature and have same characteristics of parents
  • Seeds from varieties usually have same characteristics
  • Always written in lower case
  • Hybrid:

  • Crosses between species or different parentage in the species
  • Seeds rarely breed true
  • Cultivar:

  • Cultivated variety, created by humans. Some are mutations, some are hybrids of two plants.
  • Seeds don’t usually breed true, propagation by cloning is needed ( from cuttings, tissue culture )
  • First letter of a cultivar is capitalized
  • Heirloom:

  • Varieties found in nature for at least 50 years
  • The Plant List on going list of all known plant species

    Seeds: Species, F1, F2, F3

    P1 Species seeds are from two parents of the same species or self pollination
    — breed true

    F1 seeds are hybrids created from two unrelated parents ( children )
    — hardy crosses, usually vigorous, healthy plants, children usually look like the children

    F2 are self pollinated F1s or pollinated by other F1s ( grandchildren )
    — might look like parent, might look like mailman, most diverse, greatest diversity in this cross

    F3 are self pollinated F2s or by other F2s ( great grandchildren )
    — who knows? usually selected to strengthen an F1 trait

    F4, F5, F6 can also be found

    The ‘F’ is short for filia

    Species seeds are the most expensive, each F? gets cheaper the farther you travel down the family tree

    S seeds are self fertilized seeds that have been treated chemically, or otherwise, to create a mutation. It’s not an accepted botanical grading, but often used by hobbyists

    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 $$$

    Flowering plants downsized DNA to take over world

    The abrupt origin and rapid diversification of the flowering plants during the Cretaceous has long been considered an “abominable mystery.” While the cause of their high diversity has been attributed largely to coevolution with pollinators and herbivores, their ability to outcompete the previously dominant ferns and gymnosperms has been the subject of many hypotheses. Common among these is that the angiosperms alone developed leaves with smaller, more numerous stomata and more highly branching venation networks that enable higher rates of transpiration, photosynthesis, and growth. Yet, how angiosperms pack their leaves with smaller, more abundant stomata and more veins is unknown but linked—we show—to simple biophysical constraints on cell size. Only angiosperm lineages underwent rapid genome downsizing during the early Cretaceous period, which facilitated the reductions in cell size necessary to pack more veins and stomata into their leaves, effectively bringing actual primary productivity closer to its maximum potential. Thus, the angiosperms’ heightened competitive abilities are due in no small part to genome downsizing.

    read the paper

    Article in Quanta Magazine

    Rip Van Winkle effect allows plants to survive

    image source

    Scores of plant species are capable of living dormant under the soil for up to 20 years, enabling them to survive through difficult times, a new study has found.

    An international team of academics has found that at least 114 plant species from 24 different plant families, from widespread locations and ecological communities around the world, are capable of prolonged dormancy as adult plants, remaining alive in the soil but not emerging from the ground every spring. This behaviour enables them not only to survive through difficult times, but to make the best of adversity. … more

    Shefferson Lab for Plant Fungal Evolutionary Ecology

    Giant tree forests need 59″ rain per year to form

    source

    Tree canopies come in two main heights ~82′ and 131′. They form in tropical and temperate regions but only if the yearly rainfall is consistently 59″ or more


    Rainforests are among the most charismatic as well as the most endangered ecosystems of the world. However, whereas the effects of climate change on tropical forests resilience is a focus of intense research,the conditions for their equally impressive temperate counterparts remain poorly understood,and it remains unclear whether tropical and temperate rainforests have fundamental similarities or not.Here we use new global data from high precision laser altimetry equipment on satellites to reveal for the first time that across climate zones ‘giant forests’ are a distinct and universal phenomenon, reflected in a separate mode of canopy height (~40m) world-wide. Occurrence of these giant forests (cut-off height > 25 m) is negatively correlated to variability in rainfall and temperature. We also demonstrate that their distribution is sharply limited to situations with a mean annual precipitation above a threshold of 1500 mm that is surprisingly universal across tropical and temperate climates. The total area with such precipitation levels is projected to increase by ~4 million km2globally. Our results thus imply that strategic management could in principle facilitate the expansion of giant forests, securing critically endangered biodiversity as well as carbon storage in selected regions

    A Global Climate Niche forGiant Trees