harsh bais department of plant & soil sciences probiotics for plants
TRANSCRIPT
Harsh BaisDepartment of Plant & Soil Sciences
Probiotics for plants
Plants, like most animals, are multicellular eukaryotes
BacteriaArchaea Animals
Plants
Fungi
Common ancestors
Photo credits: Public Health Image Library; NASA; © Dave Powell, USDA Forest Service; tom donald
Plants are diverse
Green algaeLiverworts
Mosses
Vascular Plants
Club mosses
Ferns
Seed Plants
Flowering Plants
Cone-bearing plants
GrassesBroad-leafed plants
Land Plants
Plants have evolved the ability to thrive in diverse land habitats.
Images courtesy tom donald
Plants are amazing living organisms
Largest flower (~ 1m)
Longest living (~ 5000 years)
Largest organism (> 100m)
Photo credits: ma_suska; Bradluke22; Stan Shebs
But why do we study them?
The world population grows and grows ...
The world population is expected to triple between 1950 (2.5 billion) and 2020 (7.5 billion)
The world population grows and grows ...
A major objective of plant science is to increase food production; current estimates indicate that we need to increase production by 70% in the next 40 years.
Food security is a major global issue
Global food shortage is a reality not a myth.
Globally, more than one billion people per year are chronically hungry
That’s more than the total population of the USA, Canada and the EU.
(Source: FAO news release, 19 June 2009)What is the major cause for loss in crop yield ?
9
60%
45%
55%
65%
Environmental stress
By developing plants that: are drought or stress tolerant require less fertilizer or water are resistant to pathogens are more nutritious
Plant scientists can contribute to the alleviation of hunger
What have we done to increase crop productivity.
Agricultural fertilizer use is a considerable source of environmental pollution
Photo courtesy of NASA/Goddard Space Flight Center Scientific Visualization Studio)
Fertilizer run-off causes dead zones, algal blooms that then decay, reducing oxygen levels in the water and making animal life impossible
Other approaches to increase crop yield.
Green revolution and fertilizers:
Other approaches for crop enhancement & protection:
TransgenicConventional
breeding BIOLOGICALS
Time >>>>>>Regulation/approvals>>>Perception --
Time >>>>Resistance >>
Rapid <<Low-Resistance <<Perception ++
It’s a microbial world
14
The probiotic BOOM!
1. A harmless bacterium that helps to protect the organism from harmful bacteria2. A substance that encourages the growth of natural healthy bacteria in the organism
The concept of Good, Bad & Ugly
Plants Perspective
Gut Microbiome, health & disease
Zones to study plant-microbe interactions:
•Phyllosphere•Rhizosphere•Endosphere
Image courtesy: The Scientist
Beneficial plant-microbe interactions
In 1 teaspoon of soil there are…In 1 teaspoon of soil there are…
Bacteria 100 million to 1 billion
Fungi 6-9 ft fungal strands put end to end
Protozoa Several thousand flagellates & amoebaOne to several hundred ciliates
Nematodes 10 to 20 bacterial feeders and a few fungal feeders
Arthropods Up to 100
Earthworms 5 or more
Free living v/s endophytic lifestyles
Applications: Agriculture productivity, biomass, biofuel & therapeutics
For
mor
e in
fo:
See
“Je
wel
s of
Jun
gles
”
Microbial Biofilms
How do plants and microbe interact?
How do plants communicate?Talking trees
Chemical signals
Bacillus subtilisArabidopsis thaliana
Bacillus subtilis forms biofilm on Arabidopsis roots
Rudrappa et al. (2007) Planta; Rudrappa et al. (2008) Plant Physiology; Lakhsmanan et al., 2012 Plant Physiology; Laksmanan et al. 2014
QuestionsQuestions
Do plants actively recruit beneficial Do plants actively recruit beneficial microbes belowground?microbes belowground?
What are the cause & consequences What are the cause & consequences of beneficial root binding on plant of beneficial root binding on plant fitness, disease protection and food fitness, disease protection and food safety ?safety ?
What do we know about botanical cry’s in plants
Heil and Bueno, PNAS (2007)
Do plants carry both public and private messages?
24
Plants Talk. Plants Listen. Here's How
25
Control MockPathogen
Bacillus binding on roots
How do roots respond upon leaf attack
Rudrappa et al. (2007) Planta; Rudrappa et al. (2008) Plant Physiology; Lakhsmanan et al., 2012 Plant Physiology; Laksmanan et al. 2014
How belowground beneficial microbes impact phyllosphere microbiome?
Pathogens use stomates as entry points
Oliamet and Holly 2012, Food Microbiol
Kumar A et al. (2012) Plant Journal
Pathogen opens the stomata in A. thaliana
Bacillus subtilis causes stomatal closure in A. thalianaBacillus-root -3hControl
Bacillus-leaf-3h Bacillus + Pathogen-3hKumar A et al. (2012) Plant Journal
How does it relate to REAL plants?
Ola
imet
an
d H
olly
20
12, F
ood
Mic
rob
iol
Foodborne pathogens use stomates as entry points in leafy greens
Bacillus subtilis causes stomatal closure in Spinach
Markland et al. (Unpublished)
Un
trea
ted
Bac
illu
s T
reat
ed3hr pst
3hr pst
Other plants traits that can be targeted using BIOLOGICALs
Mock Bacillus
Biomass Drought
Blast infections in Rice Root architecture in legumes
Control Bacillus
Control Infected Rice isolate
Control Bacillus treated
Other bacterial strains
Summary• Plants actively recruit beneficial microbes
belowground under foliar pathogen attack.• Beneficial root binding closes entry points restricting
foliar pathogen invasion.• Stomatal closure by beneficials may have
implications to increase food safety in leafy greens. • Different traits related to growth, yield and protection
against pathogens could be targeted using BIOLOGICALs.
Bais Lab members:Dr. Thimmaraju Rudrappa (Postdoc)Meredith Biedrzycki (Ph.D. student)Dr. Venkatachalam Lakshmanan (Postdoc)Dr. Gurdeep Bains (Postdoc)Dr. Amutha Sampat Kumar (Postdoc)Dr. Deepak Shantharaj (Postdoc)Carla Spence (Ph.D. Student)Emily Alff (M.S. Student) Bhavana S. Agarwal (Ph.D. Student)Amanda Roberson (Ph.D. Student)Dr. Shail Badal (Postdoc)
Collaborators:Sarah Markland (Ph. D Student) (Kniel Lab)Dr. V. Sundaresan and Sundar Lab (UC Davis)Dr. Nicole Donofrio & Donofrio Lab (UD)Dr. Paul W. Pare (Texas Tech. U.)Dr. Kirk Czymmek (Carl Zeiss Co.)Dr. Jeff Caplan (UD)Dr. Kali Kniel (U. Delaware)Dr. Janine Sherrier (UD)Dr. Dan Kearns ( Indiana U.)Dr. Angelia Seyfferth (U. Delaware)Dr. Flavio Mederious (UFLA, Brazil)
Plant Genome Research Program (NSF-PGRP)
Acknowledgments
36
“While we animals were busy nailing down things like locomotion and consciousness, the plants acquired an array of extraordinary and occasionally diabolical powers by discovering how to synthesize remarkably complicated molecules.”
Michael Pollan,
Botany of Desire