In recent years, biochar application to soil has become more popularized due to its potential roles on soil fertility, plant growth, and development. In this review, we discussed the impact of biochar on the relative abundance of soil proteobacteria and its relationship with soil physiochemical properties under different rhizospheres. It was observed that biochar applied to different soil improved proteobacteria, and its lowest and highest relative abundance was ranged from 30-80%, respectively. A positive relationship of soil proteobacteria with soil pH, total nitrogen, available phosphorous, available potassium, total carbon were observed in  several studies. Both the relative abundance of proteobacteria and its relationship with soil properties depend on biochar type, soil type, and fertilizers applied to the soil. Most of the ammonia-oxidizing bacteria including nitrogen-fixing bacteria, ammonia-oxidizing bacteria, cellulose-decomposing bacteria, nitrifying bacteria, and denitrifying bacteria belong to proteobacteria, which plays a significant role in nitrogen recycling that is beneficial for the plant growth, yield and fruits/seeds quality. Furthermore, a positive relationship between soil proteobacteria and plant yield was also highlighted. In this context, the use of biochar plays a potential role to improve the relative abundance of proteobacteria in sustainable agriculture. We highlighted future research guidelines that might benefit the sustainable agricultural system. Moreover, further studies are needed to explore the potential role of biochar application on Proteobaceria families such as Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Deltaproteobacteria, and Epsilonproteobacteria.

Stripe rust or yellow rust is a serious threat to wheat production worldwide. This disease is caused by the fungus Puccinia striiformis f.sp. tritici (Pst). Currently it is controlled by the use of resistant wheat cultivars and fungicides. However, Pst can rapidly mutate to overcome the plant resistance while the excessive use of fungicides is not environment friendly. Therefore, modern tools and technologies are required to overcome this devastating disease. There are increasing evidences about the up-regulation of the fungal genes involved in the transport of ammonium and sulfur from the host, thiamine biosynthesis and cytochrome P450 enzyme are during Pst infection of wheat. Hence, one of the potential strategies to combat the stripe rust is to target these genes using RNAi technology to produce Pst resistant transgenic wheat. This will increase our understanding about the actual roles of the genes involved in ammonium and sulfur transport, thiamine biosynthesis and cytochrome P450 enzyme. Coupled with RNAi, the use of other novel technologies will be useful in developing multi-disease resistant crops. The present review is focused on the recent research breakthroughs and future challenges and opportunities towards development of rust resistant wheat varieties.

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