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Natural products obtained from microbes, plants and animals find their potential use as biofertilizers and biopesticides sustaining and enhancing crop production and protection. Among them microbes and their metabolites with excellent plant growth-promoting and biocontrol properties have been identified, mass produced successfully, appropriately formulated and are commercially available for use. Compounds of microbial origin which make them efficient biofertilizers and biopesticides enhancing plant growth and providing protection from various biotic and abiotic stress include production of plant growth-promoting hormones like auxins, giberrelins, cytokinins and 1-aminocyclopropane-1-carboxylate deaminase (ACCD); production of antagonistic compounds such as antibiotics, crystal proteins, hydrolytic enzymes, siderophores, hydrogen cyanide, etc. Additionally, these beneficial microbes also compete for food and habitat with phytopathogens or parasitize the pests and eliminate them. Majority of the microbes and their bioactive molecules are target specific, eco-friendly and biodegradable and play an important role in preserving the ecosystem. These eco-friendly natural products could either supplement or replace the hazardous agrochemicals thereby minimize or nullify their use. Screening and selection of the microbial strains based on its geographical origin will make the bioformulation more suitable for a particular agroclimatic condition, and this needs intensive studies on microbial ecology and interaction with other components of the ecosystem. Research focus on ways to improve the efficacy of these biomolecules, and mass production of these natural products for its utilization and commercial availability will build a path towards environment-friendly agriculture. Alternatively, research that focusses to elucidate the chemistry of natural compounds and to synthesize compounds that mimic them is also being done to ensure the demand-supply balance. This chapter will shed light on potentials and prospectives of the use of natural bioactive compounds of microbial origin in enhancing crop protection and yield.

Plant microbiome refers to the diverse microbial counterparts that are associated with plants and plays a crucial role in host biology, ecology, and evolution. Though plant microbiomes have history of co-evolution with the host plants, certain members other than the core-microbiomes are shaped by various factors including plant genotype, plant age, associated host plant tissue or organ, other interacting microbial associates, arthropods, various environmental factors such as soil physio-chemistry, and human inference such as crop domestication, intensive and extensive cultivation, and use of agrochemicals especially in case of agro-ecosystems. Classical knowledge based on microbial culturing techniques and biochemical analysis prejudiced that when a plant interacts with a microbial partner the relationship could be detrimental as with pathogen interaction or promote plant growth in case of symbiotic associations. Advances in molecular techniques such as culture-independent approaches, next-generation sequencing, and high-throughput screening methods helped us to understand the robust nature of plant-associated microbiomes and their crucial role in plant fitness, environmental protection, and human health. This chapter gives a glimpse of patterns of plant microbiome associations and their importance in plant health and emphasise the importance of both basic and applied research which will enlighten us with deeper insights on the plant microbiomes. This will help us identify economical, eco-friendly, and effective strategies of manipulating the plant-associated microbiomes which can open up new avenues in maintaining plant health and ecological fitness and sustain crop production in a clean green way preserving the nature’s serenity and human health.

Entomopathogenic microbes viz., bacteria, actinomycetes, fungi, virus, protozoans; microbial metabolites; phytochemicals from plants viz., neem, chrysanthemum, tobacco, derris, basil, citrus, etc., and compounds of animal origins viz., nereistoxin and insect pheromones have evidenced excellent protection against crop pests and are commercially available. Most of these microbes and bioactive molecules of natural origins are target specific, biodegradable, and eco-friendly. Insecticides from natural products will act as an effective alternative to pollution-causing synthetic agrochemicals with high health hazard to nontarget organism in the ecosystem. Extensive research to screen and identify environmentally safe biomolecules of natural origin with high efficacy against target organisms and intensive studies on their biological activity, mode of action, and ways to enhance their bio-efficacy using biotechnological tools may help in improving their bioactivity and target specificity. This chapter discusses about diverse group of entomopathogens, microbial metabolites, botanicals, insecticidal toxins of animal origin, and semiochemicals conferring plant protection against herbivorous insect pests and their potential application for crop protection.

The association of plants and microbes has begun since their evolution. Microbes and plants have coevolved and interacted with each other to meet their demands. Their relationship might be cordial symbiotic as in case of interaction between plants and beneficial microbes or detrimental as in case of interaction between plants and phytopathogens. Numerous genera of microbes are known to be associated with the plants and their rhizosphere. The interaction among these diverse microbial communities and their ability to excel the competition decides the overall plant health. In the past decades, agricultural microbiologists had given more emphasis to plant growth-promoting rhizosphere microbes and soilborne phytopathogens and their interactions, which has resulted in the identification and use of promising microbial strains with biocontrol and biofertilizing properties. With recent advancement in molecular diagnostics, it is evidenced that in addition to rhizosphere microbes, the interactions between plant microbiomes, viz. epiphytes and endophytes, colonizing the entire plant and the plant genome (holobiont) significantly affect the fitness of the plant. Scientific studies evidence that the plant genotype, biostage, soil biogeochemistry and microbe-microbe interaction decide the nature of associated microbiomes. Recent research shows that artificial inoculation of beneficial microbiomes instead of a single or a consortium of microbial strains would improve the success rate of establishment and functioning of the introduced microbial community. This chapter highlights the recent advancements in plant-microbe interaction and ways it could be explored and exploited to enhance plant health, thereby improving crop production qualitatively and quantitatively supporting sustainable agriculture.

We present and experimentally evaluate spread identity -- a new dynamic network address remapping mechanism for Internet connections that provides anonymity and DDoS defense. For each session between a source and destination host, the trusted source gateway dynamically and randomly assigns an IP address for the source from the pool of all routable IP addresses within the source organization. Similarly, in response to a name resolution query from the source gateway, the trusted authoritative DNS server for the destination host dynamically and randomly assigns an IP address for the destination from the pool of all routable IP addresses within the destination organization. Moreover, different hosts can share the same IP address when communicating with distinct peers. Each gateway creates a NAT entry, valid for the communication session, based on the dynamic assignment by its organization. An eavesdropper listening to packets flowing through the Internet between the source and destination gateways learns only the source and destination domains; the eavesdropper cannot see the actual complete IP addresses of the source and destination hosts. In addition, spread identity enhances DDoS defense capabilities by facilitating filtering of packets based on destination address. Whereas a traditional IP source address can be spoofed, with spread identity the destination address cannot be spoofed. Therefore, using multiple IP addresses for the same destination enables simple and powerful DDoS protections that block attackers without necessarily blocking legitimate users. Our ns-2 simulations demonstrate that file transfer success rates for our spread identity DDoS protection mechanism are similar to those of filter- and capability-based approaches, with lower file transfer times than for filter-based approaches. Deploying spread identity requires changes to organizational gateways but not to Internet routers. Another cost is increased DNS traffic, but unlike overlay-based DDoS defense approaches, spread identity does not increase overall communication network latency. A partial form of spread identity implemented only at the destination facilitates destination-based filtering without providing sender anonymity.