International experts have described for the first time how healthy plants
appear to carry bacteria in their cells, opening a new avenue of research to
improve future plant health and propagation efforts—including food crops
such as grains and fruit such as grapes.
The Indian and Australian experts have used various high-tech laboratory
methods to describe how endophytic bacteria can exist inside plant cells,
leading to the "baffling" concept of "alien life" in healthy plant cells.
"It's baffling how this bacterial association in cell cultures escaped the
attention of plant biologists and microbiologists considering that this is a
widespread phenomenon in plant tissue cultures we tested, and the in-vitro
cultures have long been used in both basic and applied research," says
senior Flinders University Professor Chris Franco.
Naming them Cytobacts, research collaborators Dr. Pious Thomas, previously
from the Indian Institute of Horticultural Research and Flinders Emeritus
Professor Franco say cytobacteria have been widely observed in
micro-propagating stocks in crops including banana and papaya.
The article, "Intracellular Bacteria in Plants: Elucidation of Abundant and
Diverse Cytoplasmic Bacteria in Healthy Plant Cells Using In Vitro Cell and
Callus Cultures," by T Pious and CMM Franco, has been published in
Microorganisms .
Dr. Thomas, now CEO and director of Thomas Biotech and Cytobacts Center for
Biosciences in Bengaluru, India—who commenced the study during a research
stint at Flinders University 10 years ago—has published the results with
senior Flinders University medical biotechnology researcher Emeritus
Professor Franco.
"I am excited to expand this new field of plant cell biology in my R&D
center at Bengaluru with the plan to focus on endophytic microorganisms and
allied areas with a primary focus on micropropagation of papaya which is
severally hampered due to interference from microbial contaminants," says
Dr. Thomas, who worked with Professor Franco as a visiting scientist at
Flinders University 10 years ago.
"Normally the endophytic bacteria are known to reside between plant cells.
Because plant cells are considered to be free of other living organisms it
goes against the grain to report bacteria within plant cells," he says.
"We need new tools to be able to study the role of these intracellular
bacteria in healthy plants which are not normally amenable for conventional
microbiological methods," he says.
"This new paradigm of cytobacteria in health cells has the potential to open
up a whole new area of research, including plant biology, human health and
environmental microbiology," Professor Franco says.
Veteran biotechnology scientist Flinders University Professor Franco retired
from Flinders University's College of Medicine and Public Health this year
with more than 100 papers to his credit in a long research career.
He says the milestone study suggests that Cytobacts have possibly adapted in
plant species after losing some of their functions and ability to synthesize
compounds so they become obligate symbionts of the plant cell.
"Potentially they are involved in some of the integral functions of plants,
such as energy metabolism, or as an inducer of defense responses against
other microorganisms."
Reference:
Pious Thomas et al. Intracellular Bacteria in Plants: Elucidation of
Abundant and Diverse Cytoplasmic Bacteria in Healthy Plant Cells Using In
Vitro Cell and Callus Cultures, Microorganisms (2021). DOI:
10.3390/microorganisms9020269