In many species of the Fabaceae family, no galls or nodules are observed in the root system. Will there be nitrogen-fixing bacteria (endophytes) that do not induce nodule formation?
Some plants outside Fabaceae do have N-fixing endophytes (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4437324/).
I guess that the number of species of such bacteria is higher than nodule-forming bacteria.
A couple of legume species growing in the tropics produce nodules aerially on their stems. These species are tropical species which grow in periodically flooded soils. Many plants form nodules and actinomycetes are involved in the nitrogen fixation. The fixation of Nitrogen has been demonstrated in tropical grasses without any nodulation as in the other systems.
Dear Aguilera,
Some bacteria are free-living N2-fixing bacteria and these bacteria adapted to their environment (see Beauchamp et al. Bioresource Technology 97(8):1002-11 · June 2006). These free-living N2-fixing bacteria could be rhizosphere inhabitant, but they will not induce nodule. Bacteria, like rhizobium, have a signaling pathways with their hosts, and some hormone productions (ex. : IAA) are required to induce the root cells reprogramming for nodule development.
Kind regards,
I just want to add some, Nodule can not be formed in non leguminous plants such as rice, maize..
No, there are a number of free-living and symbiotic Nitrogen fixing bacteria and bluegreen algae that do not form nodules. One of the classic ones that is used to increase nitrogen in rice culture is associated with the water fern. Azolla is a free-floating water fern and has agronomic importance due to its ability to fix nitrogen (Singh 1977). It forms a nitrogen-fixing symbiosis with the cyanobacterium Anabaena azollae, which is present in the leaf cavity of the fern (Watanabe 1982, spore 1992). There is a large herbaceous plant in the neotropics (genus is Gunnera) that has bluegreen algae inside the lower part of the stem. There are other N-fixing bacteria that live in root rhizospheres/ on the surfaces of roots.
149
HI Narciso
Many useful references 1
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2768939/
3
http://horticulture.tekura.school.nz/soils/soils-2/ht1032-soils-2-study-plan/soil-organisms/
8
https://www.freshfromflorida.com/content/download/10893/141649/nem102.pdf
14
http://www.hypertextbookshop.com/biofilmbook/v005/r002/Contents/01_Topics/02_Chapter_2/04_Section_4/02_Intermediate/06_Page_6.html
16
https://academic.oup.com/pcp/article/46/9/1583/1812777/Cochleata-Getting-to-the-Root-of-Legume-Nodules
18
http://biblio.teluq.ca/LinkClick.aspx?fileticket=Zt582qIwcMI5ljHgoneZIw%3D%3D&tabid=40831&language=fr-CA
- Badges
- Science topic
- Similar topics
- Mathematical Sciences
- Statistics
- Statistical Software
- SPSS