Planting Pollinator-Friendly Habitat.

Climate change impacts plant physiology and phenology, and sometimes growing practices must be shifted to optimize and improve or sustain productivity. 

Pollination is the transfer of pollen grains from the anther to the stigma, which is a pre-requisite for fertilization and subsequent fruit and seed development. In the absence of pollination, even the best variety, grown under optimal agronomic conditions, cannot produce optimal yield. Therefore, adequate pollination of our crops and wild plant species is an essential requirement for crop productivity and sustenance of plant diversity, which in turn, support our essential needs such as food, shelter, fibers, medicines, clean air and water, and aesthetic cultural needs.

Plants cannot usually achieve pollination on their own as they are sedentary and cannot move pollen from the another to the stigma. Instead, they have recruited other agencies-- animals, wind and water--to perform this function. Nearly 90% of plant species are pollinated by animals (biotic pollination), largely bees and other insects (such as wasps, flies, beetles, moths and butterflies), birds and bats, and the remaining species are pollinated by wind or water (abiotic pollination). Out of 115 leading world food crops, 87 are pollinator-dependent and produce 35% of global food. Pollinator-dependent crops include legumes, oil crops, and fruit and vegetable crops, which add nutritional value to our diet. The interaction between plants and pollinators is mutualistic---a short of 'Biological Brother'; plants exchange their resources for pollination services by animals.

Insects, particularly bees, are the most dominant pollinators of crop species. There are about 20,000 bee species worldwide, and many of them are active in pollination. The Earthwatch Institute, an international organization, dealing with the environment and conservation, has declared the bee as "the most important living being on the planet", and the United Nationals has declared May 20th as the 'World Bee Day' to recognize the role of bees in pollination and other key ecosystem services. 

This article highlights the serious crisis bees and other pollinators face in the recent decades that has led to grave concerns around the world about the pollination of crops, its impact on food and nutritional security of humans, and the concerted attempts being made to sustain pollinators.

The drivers of the decline in pollinators have been largely human-induced habitat degradation, excessive use of unfriendly agro-chemicals, particularly pesticides and herbicides, a number of diseases affecting pollinators, and climate change.

The effects of pesticides and herbicides on pollinators have been studied since long, although mostly on honeybees, and considerable data is available on their negative effects.

The realization of the problems associated with the dependence on one honeybee species (Apis mellifera) for crop pollination led to increased efforts to domesticate other wild bee species. Considerable progress has already been made along these lines. A number of stingless and solitary bee species, such as alkali bee (Nomia melanderi), alfalfa leafcutting bee (Megachile roundata) and mason bee (Osmia spp), which are very effective pollinators for a range of crop species have been domesticated. They can be used singly or in combination with honeybee colonies for pollination services. Carefully conducted research in recent years has also shown that wild pollinators, largely bees and other insects, also play an important role in pollinating crop species even in the presence of managed pollinators. Studies conducted by over 65 researchers covering 41 crops from 600 field sites world-wide showed that the enhancement of fruit set in crop species by honeybees and wild insects is independent. Thus, managed bees supplement rather than substitute wild bees in pollinating crop species.

Therefore, the present trend is to sustain crop pollination services by 

1. The judicial use of managed pollinators (combining honeybees and other domesticated solitary bees) and

2. Increasing the density and diversity of native pollinators by making the agricultural habitat pollinator-friendly.

Fig: Engineered S. alvi colonizes and functions in bee guts

Attempts are also being made to develop control measures for pests and diseases of honeybees using novel approaches. Recently, it has become possible to use engineered symbiotic gut bacteria ( Snodgrassella alvi) of honeybees to alter host gene physiology, behavior, and growth to improve bee survival after a viral challenge and also to kill parasitic Varroa mites by activating RNAi response of the time. Although this revolutionary approach is yet to be demonstrated in the field, it has the potential to provide cheap, long-term, and easy to apply technology to solve some problems that honeybees face. Another approach being explored to sustain crop pollination in the future is the development of 'pollinator drones'. These drones have shown their ability to bring about pollination under laboratory conditions with manual guidance. With further refinements, such as the incorporated of GPS and artificial intelligence, drones may be able to carry out pollination on their own in some commercial crops in the future.

The discussion presented above highlights the global concern about declining pollinators and the enormous efforts being made in the developed world to mitigate the pollinator crisis to sustain crop productivity. Although the monoculture cropping system is not as prevalent in India as in the West, the impacts of habitat degradation, climate change, and the use of pollinators. Presently, Indian farmers are reported to use 35% more than in 2000-01. We grow a large number of pollinator-dependent crops throughout the country with considerable climatic variations. Pollination is a dynamic eco service; pollinators and their individual contributions to the pollination of crop species vary greatly in time and space. Therefore, it is necessary to study the temporal and spatial details of pollination in different crops. Our information is very meagre on these aspects. The only crop in which the use of managed pollinators is being practiced routinely is apple, largely through the efforts of the International Centre for Integrated Mountain Development. We have no detailed information about pollinators or any other approach to overcome the problem. Some limited studies available have indicated pollination deficiencies in some crops. In large cardamom, an important case crop of North-East India pollinated by bumblebees, only 30% of the flowers get pollinated due to the low density of pollinators in the orchards.

                                         Fig: BUMBLEBEE

Himalaya is one of the most ecologically fragile bio-geographic zones in India (Rodgers and Panwar, 1988). Demographic, economic and social changes, therefore, have important consequences on the conservation of Trans Himalayan natural resources.

It is one of the most diverse region and more appropriate for the study of insects due to unique ecosystems, high altitude insects are highly specialized and bio-indicators of health of Himalaya. The arid Trans-Himalayan region is convering the Tibetan Plateau and the Tibetan marginal mountains in the rain shadow of the Greater Himalayan range.

                      Fig: SAMPLING SITES: HIMACHAL PRADESH

Indian agricultural scientists have taken climate change and have been carrying out extensive studies during the last many years to take our agriculture climate-resilient.

The concept you're proposing involves utilizing engineered symbiotic gut bacteria, specifically, Snodgrassella alvi from honeybees, to enhance the resilience of bees against viral challenges and combat parasitic Varroa mites.

1. Identify Relevant Genes and Pathways: 

Understand the host genes related to immunity, antiviral defense, and growth.

Identify specific RNA interference (RNAi) pathways in the bee host that can target Varroa mites.

2. Engineer Snodgrassella alvi:

Introduce genetic modifications to Snodgrassella alvi to produce proteins or RNA molecules that influence the identified genes and pathways.

Ensure the engineered bacteria can survive and colonize the honeybee gut.

3. Bee Introduction:

Develop a method to deliver the engineered Snodgrassella alvi to honeybee colonies, possibly through sugar water or other bee-friendly mediums.

4. Viral Challenge:

Expose the treated bees to a controlled viral challenge, mimicking real-world conditions.

Monitor the survival rate, immune response, and overall health of the treated bees compared to untreated ones.

5. Varroa Mite Intervention:

Design the engineered Snodgrassella alvi to produce RNA molecules targeting Varroa mite genes involved in essential functions.

Deliver the engineered bacteria to the honeybees, enabling the activation of RNA interference in Varroa mites.

6. Monitoring and Data Collection:

Regularly assess the health, behavior, and growth of the treated honeybees.

Monitor Varroa mite populations and observe the effects of RNA interference on their survival and reproduction.

7. Data Analysis and Refinement:

Analyze the collected data to evaluate the effectiveness of the engineered symbiotic bacteria in enhancing bee resilience and controlling Varroa mites.

Refine the engineered bacteria based on the findings and repeat experiments as necessary.

8. Regulatory Approval:

Comply with regulatory standards and seek approval for the use of engineered bacteria in agricultural practices.

9. Community Engagement:

Communicate findings and potential benefits to the beekeeping community and other stakeholders.

Address concerns and ensure responsible and transparent dissemination of information.

It's important to note that this kind of genetic engineering and field testing should be conducted with careful consideration of potential environmental impacts and ethical implications.

Engineered symbiotic gut bacteria are selected as a potential tool to help honeybees for several reasons. Honeybees naturally have a symbiotic relationship with various bacteria in their gut, including Snodgrassella alvi. This symbiosis plays a role in the overall health and functioning of the honeybee digestive system. Gut bacteria have a close interaction with the host organism's physiology, including the immune system and nutrient absorption. Engineering these bacteria allows for a direct influence on the host's biology. Genetic modification of symbiotic bacteria enables targeted changes to specific pathways or genes of interest. This precision allows researchers to influence host characteristics such as immunity, behavior, and growth. Engineered bacteria can potentially activate RNA interference (RNAi) responses in the host organism. RNAi is a natural defense mechanism in insects, and by enhancing this response, it may be possible to combat specific threats, such as Varroa mites.

Honey bees are essential pollinators threatened by colony losses linked to the spread of parasites and pathogens. Here we report a new approach for manipulating bee gene expression and protecting bee health. We engineered a symbiotic bee gut bacterium, Sanodgrassella alvi, to induce eukaryotic RNA interference (RNAi) immune response. The engineered S.alvi can stably re-colonize bees and produce double-stranded RNA to activate RNAi and repress host gene expression, thereby altering bee physiology, behavior, and growth. This approach to improve bee survival following a viral challenge and that engineered S.alvi can kill parasitic varroa mites by triggering the mite RNAi response. This symbiont-mediated RNAi approach is a tool for bee functional genomics and potentially for safeguarding bee health.