Transplant, shared property of seed plants

In the early January, the announcement of the first transplant of a porcine heart on an American patient left in the shadow another feat of graft, in plants this time. In An article published on December 22 in The Journal Nature , a research team from the University of Cambridge demonstrates that the transplant is a common property of seed plants, shared by one of the largest groups of terrestrial plants: monocotyledons. This group of plants includes many species that are familiar to us – bamboo grass via the snowcraft – and a wide variety of large-scale cultivated species, among which grass cereals but also onions, the onions, Asparagus, ginger, pineapple, vanilla …

 Palm image Dattier 2.5 years after the transplant. The insert shows an enlarged region at the base of the plant, the tip of the arrow pointing towards the junction of the graft. Credit

While the graft is a long-standing technique for the cultivation of fruit trees and conifers, So far had never been obtained in monocotyledons. The hypothesis issued to explain this failure held in the absence of plants in this group, from the cambium, a layer of small cells that allow secondary growth. plants, and the source of new vessels necessary for the circulation of Sèves.

The researchers assumed that plasticity properties similar to those of the cambium could be present in the young shoots, when they are still in the embryonic state. They have therefore undertaken to try grafts just after seed germination, and found that they could take if they choose for an area of ​​the young rod located between the Cotyledon and the root embryo. Grafts and grafts were then developed normally, whether for grafts between plants of the same species or different species. The growth of a grafted dattier palm was then followed for two years without rejecting transplant. Even species such as rice and millet, remote to the point of not using the same photosynthesis mechanisms, could be grafted on the other successfully.

On either side of the junction between grafts and graft, the cells are reorganized, healing the breach and, above all, restore vascular connections. The circulation of Pit is then ensured, in the same way as the blood circulation between the body and the graft is imperative during an organ transplant. The repair process involved is very similar, in its molecular mechanisms, which had been previously described in other seed plants. Thus, despite the absence of cambium in monocotyledons, some embryonic tissues fulfill the same regenerative function during a transplant.

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/Media reports.