**6. Symbiotic relationship of cowpea for environmental protection**

Legume plants are known to form symbioses with extremely broad range of beneficial soil microorganisms (BSM), the examples of almost all plant-microbe mutuality systems present in soil. The different legume plants have interaction with many beneficial microorganisms to increase nutritious, minerals and also do the intake of water from soil via prominent root hairs (**Figure 9**).

Cowpea plants promote the other plant development and also give protection to many bacterial of fungal plant pathogens and insect-pests. In the field of environmental sciences and agricultural aspects, the cowpea consider do most important beneficial legume to do the symbioses, they are bacterial specifically root nodule (RN) symbiosis and the fungi particularly arbuscular mycorrhiza (AM).

These symbioses explains the metabolic and genetically relations with host plants and have that plant growth promoting rhizosphere bacteria which are

#### **Figure 9.**

*Cowpea (Legumes) involved in N2 fixation and Carbon fixation. Courtesy: Sanjay K. Jaiswal, Frontiers in Sustainable Food Systems.*

Vigna unguiculata *(L.) Walp: A Strategic Crop for Nutritional Security, Well Being... DOI: http://dx.doi.org/10.5772/intechopen.103025*

beneficial endophytic bacteria interact with legumes such as cowpea. The RNS requires a set of genes belonging to common symbiosis signaling pathway (CSSP), most of which are present in all land plants including legumes that can form a second symbiosis with, the fungi arbuscular mycorrhiza (AM) [14, 15].

Legumes are able to fix nitrogen from the air in symbiosis with Rhizobium bacteria [16]. The symbiotic relationship between plants with Rhizobium bacteria or any fungi to do fix the atmospheric nitrogen and compensate the ecological gas balance and also do the growth of crop plants to ultimately improve agriculture and maintain sustainable development of life.

The cowpea plants is eager to absorb high heavy metals such as copper from highly polluted soil or industrial effluents or etc., so it is otherwise called hyperaccumulator plants [17]. The cow pea consider as great pollution eradicator.

## **7. Conclusion**

Cowpea have morphologically and taxonomically well adapted in tropical countries. The herbaceous nature of cowpea is easy for crop cultivation, crop rotation as well as intercrop. It have able to withstand drought or seasonal conditions. The nutrient aspects have more starchy content to proof that stable food for poor people. Cowpeas have other high protein less fat and high vitamins and minerals for maintain excellent metabolism for consuming organisms. Cowpea do fixing atmospheric nitrogen by to symbiotic relations with microorganisms with do recycling with biogeochemical cycles to enhance atmospheric gases.

The cowpea is one of the the largest cultivator crop among legume family and is commonly cultivated crop in most of the countries globally. The cow pea has highest nutrient values so used for maintain good nutrient calories required for our body. This crop plant is considered as good medical applications to cure or reduce the most non-communicable diseases in animals and or human systems. Cow also pea maintain ecological balances by fixing nitrogen, to chelate heavy metals for water and soil pollution removal and it used as bio-fuel production to improve our green environment and reduce fossil fuels to control other environmental pollutions.

#### **8. Summary**

*V. unguiculata* (L.) Walp is considered as green vegetable crop and the dried seeds were placed in pulses. Excellent to cultivation of the crop in any soil type and able to grow most arid climates and induce and develop more farm industries in global scale. Cowpea has poor digestion ability and considered as most stable food for very poor or developing countries. In Neolithic times the black eyed seed is most common starchy food. This crop have more chances to grow in tropical lands.

The morphological aspects ultimately deals with, the cowpea is recognized as an annual crop, herbaceous woody and greenish in nature. The seedlings were early to germinate in less moisture conditions. Cowpea leaves are rich in main green pigments such as chlorophyll *a* and chlorophyll *b* and also have reticulate venation made by vascular bundles. Inflorescence of the plant is raceme with five free petals with five fused sepals. The Androecium is nine plus one in number and is responsible for the development of male gametes. The gynoecium is ready to provide an egg. The double fertilization of the egg with pollen grain to fuse to form fertile black eyed seeds. The seeds nutritional information of cowpea deals with the presence high concentrations of carbohydrates, proteins, minerals and vitamins. The major ingredient is starch among the chemical components was highly recommended.

All vitamins regulate metabolism, specifically high concentration of niacin as coenzymes in cowpea and improve cellular growth. The irons and phosphorous are dominant minerals present in cowpea to regulate growth anabolism and catabolism.

The medical aspects enumerate the cowpea is no limit. The cowpea has high potassium to improve cell signaling in animals. The legume lowers the blood glucose level to reduce the diabetes among humans and it lowers blood cholesterol. The seeds have high in full of dietary fibers to regulate metabolism. The fiber content of cowpea is responsible to maintain very low fat in our body. Cowpeas have marvelous cell antioxidant mechanism to remove reactive oxygen species and reduce the effect certain toxic substances due to stress and radiation. The seeds rich in protein contents, the ingredients of cowpea show wonderful circulatory system and improve cardiac muscle function and lower the blood pressure. The black eyed seeds also induce gall bladder bile secretion for digestion purpose. Cowpea role in to decrease body weight, it means that improve weight loss.

The ecological review deals with by symbiotic relationship among various types of beneficial microorganisms. The root nodules of cowpea have to fix atmospheric nitrogen to ammonia with the help of *Vesicular Arbuscular Mycorrhiza* fungi and also certain bacteria like *Rhizobium* and other some organisms. The *Agrobacterium* also do fix atmospheric nitrogen to by *Nif* genes cowpea induce their flavonoids with acetosyringone to transfer DNA to host plant induce cancers or other mechanisms to improve growth of crop plants.
