Endophytic bacteria colonize plants and live inside them for part of or throughout their life without causing any harm or disease to their hosts. The symbiotic relationship improves the physiology, fitness, and metabolite profile of the plants, while the plants provide food and shelter for the bacteria. The bacteria-induced alterations of the plants offer many possibilities for biotechnological, medicinal, and agricultural applications. The endophytes promote plant growth and fitness through the production of phytohormones or biofertilizers, or by alleviating abiotic and biotic stress tolerance. Strengthening of the plant immune system and suppression of disease are associated with the production of novel antibiotics, secondary metabolites, siderophores, and fertilizers such as nitrogenous or other industrially interesting chemical compounds. Endophytic bacteria can be used for phytoremediation of environmental pollutants or the control of fungal diseases by the production of lytic enzymes such as chitinases and cellulases, and their huge host range allows a broad spectrum of applications to agriculturally and pharmaceutically interesting plant species. More recently, endophytic bacteria have also been used to produce nanoparticles for medical and industrial applications. This review highlights the biotechnological possibilities for bacterial endophyte applications and proposes future goals for their application.

In this study, 15 bacterial endophytes linked with the leaves of the native medicinal plant Pulicaria incisa were isolated and identified as Agrobacterium fabrum, Acinetobacter radioresistant, Brevibacillus brevis, Bacillus cereus, Bacillus subtilis, Paenibacillus barengoltzii, and Burkholderia cepacia. These isolates exhibited variant tolerances to salt stress and showed high efficacy in indole-3-acetic acid (IAA) production in the absence/presence of tryptophan. The maximum productivity of IAA was recorded for B. cereus BI-8 and B. subtilis BI-10 with values of 117 ± 6 and 108 ± 4.6 μg mL⁻¹, respectively, in the presence of 5 mg mL⁻¹ tryptophan after 10 days. These two isolates had a high potential in phosphate solubilization and ammonia production, and they showed enzymatic activities for amylase, protease, xylanase, cellulase, chitinase, and catalase. In vitro antagonistic investigation showed their high efficacy against the three phytopathogens Fusarium oxysporum, Alternaria alternata, and Pythium ultimum, with inhibition percentages ranging from 20% ± 0.2% to 52.6% ± 0.2% (p ≤ 0.05). Therefore, these two endophytic bacteria were used as bio-inoculants for maize seeds, and the results showed that bacterial inoculations significantly increased the root length as well as the fresh and dry weights of the roots compared to the control plants. The Zea mays plant inoculated with the two endophytic strains BI-8 and BI-10 significantly improved (p ≤ 0.05) the growth performance as well as the nutrient uptake compared with an un-inoculated plant.

The rapid development and expansion of modern irrigation schemes across arid environments have radically transformed both natural environments and existing agricultural systems over the past century. The consequences for natural and cultural values are often severe, but remain poorly documented for many regions. The present study describes the floristic diversity of an Oasis agro-ecosystem located in Egypt’s hyper-arid Western Desert. A total of 132 sites were chosen to represent the flora of Siwa Oasis agro-ecosystem and 154 species were recorded of which 52 were cultivated. Non-cultivated taxa consisted predominately of therophytes whereby the flora of Siwa is represented by monoregional, biregional and pluriregional elements as well as some cosmopolitan species. During field survey, 55 species were recorded for the first time suggesting the recent introduction of new weeds. Based on previous studies, 36 wetland and orchard species may have become locally extinct due to loss of habitat and extensive transformation of the Oasis agro-ecosystem. Although Siwa does not support any endemic species, this study documents a unique and complex agro-ecosystem shaped by natural and human agents over millennia. Descriptive floristic studies such as presented here are important records during a time of continuing and increasing change throughout arid regions of the world

Ginger is rich in different chemical compounds such as phenolic compounds, terpenes, polysaccharides, lipids, organic acids, minerals, and vitamins. The present study investigated the effect of mineral fertilizers on the content of mineral elements in the rhizomes of Zingiber officinale Roscoe, soil enzymes activity, and soil properties in Surkhandarya Region, Uzbekistan. To the best of our knowledge, the present study is the first in Uzbekistan to investigate the mineral elements of ginger rhizome inhabiting Termez district, Surkhandarya region. A Field experiment was conducted at the Surkhandarya experimental station research Institute. Four treatments have been studied (Control with no fertilizers (T-1), N₇₅P₅₀K₅₀ kg/ha (T-2), N₁₂₅P₁₀₀K₁₀₀ kg/ha (T-3) and N₁₀₀P₇₅K₇₅ + B₃Zn₆Fe₆ kg/ha (T-4)). Results showed that T-4 treatment significantly increased ginger rhizome K, Ca, P, Mg, Fe, Na, Mn, Zn, Si, Li, and V content as compared to all other treatments and control. T-3 treatment significantly increased Mo, Ga, and Ag content in comparison to other treatments. Soil enzymes showed a significant increase for all treatments against control, while T-4 treatment has recorded the highest enzyme activity in comparison to all other treatments in urease, invertase, and catalase content. Soil chemical properties have significantly changed for all treatments against the non-cultivated soil and the zero fertilizers plantation with variation among different treatments. Results showed that ginger root is rich in minerals and can be used as a great potential for nutritional supplements and soil enrichment. This study suggest that combination of macro-microelements have the potential to increase the content of mineral elements in the rhizomes of ginger in field conditions.

Phenotypic plasticity is frequently highlighted as a key factor in plant invasiveness, as it enables invasive species to adapt to diverse, complicated habitats. Trianthema portulacastrum is one of the most common aggressive species that threaten different crops around the world. Phenotypic plasticity in T. portulacastrum was investigated by comparing variation in germination, vegetative macromorphology, photosynthetic pigments, stomatal complexes, and seed micromorphological traits of 35 samples collected from 35 different localities. One-way cluster analysis and principal component analysis (PCA) were used to classify samples into homogeneous groups based on the measured traits. Pairwise statistical comparisons were conducted between the three resulting groups. The phenotypic plasticity index (PI) was calculated and compared among different groups of characters. Results showed that photosynthetic pigments and macromorphological characteristics had the highest PI, followed by seed micromorphology, and then stomatal complex traits, while germination parameters showed the lowest PI. We propose that soil moisture, salinity, and temperature are the most determinative and explanative variables of the variation between the three classified groups. We strongly believe that the phenotypic plasticity of T. portulacastrum will support species abundance and spread even under expected changes in climatic conditions, in contrast to the vulnerable traditional crops.