Impact of harsh environmental conditions play an essential role in the control of legume-rhizobia
interactions. They can arrest the growth, multiplication and survival of rhizobia in soil
rhizosphere. The harsh environmental conditions may also have depressive effect on the
steps involved in legume-Rhizobium symbiosis such as molecular signaling, infection process,
nodule development and function, resulting in low nitrogen fixation and crop yield. Selection
of hosts and their nitrogen-fixing endosymbionts that are tolerant to a broad range of
environmental stresses is important for agriculture system. Understanding the key molecular
factors and steps in rhizobia-legume interaction is of crucial importance for the development
of Rhizobium strains and legume cultivars with high N2-fixation potential. Prevelence
and aboundance of rhizobia species vary in their tolerance to major environment factors;
consequently, the selection of resistant strains is an important option. Better N2 fixation can
be achieved by selecting tolerance or resistance rhizobia from soil subjected to environmental
stress. The selection and characterization of harsh conditions-tolerant strains with efficient
symbiotic performance may be a strategy to improve Rhizobium-legume symbiosis and
crop yield in adverse environments. Environmental stress severely affected on various metabolic
activities of legumes including, nod gene expression, photosynthesis, synthesis of proteins,
enzymes and carbohydrates. Therefore, understanding the environmental stress–
rhizobia–legume interactions is urgently required for growing legumes under harsh environmental
stress. Research into these areas is currently underway in several research groups
throughout the world and it is anticipated that this research will provide beneficial outcomes
resulting in improved sustainability and productivity in agricultural systems

Abstract
Torrential rains (in January 2011) that have swept a limited area in the Eastern Desert, facing Assiut Province (Upper Egypt),
resulted in enriching the vegetation in Wadi Al-Assiuty and its tributary Wadi Habib. Vegetation survey carried out shortly after this
event (in May) revealed the prevalence of annuals which are hardly recognizable in such usually dry habitats. The normally scarce
perennial vegetation has flourished. A total of 66 plant species, 33 perennials and 33 annuals, belonging to 53 genera from 22 different
families were recorded. Therophytes are the predominant life form (50%) followed by chamaephytes (21%), phanerophytes (15%),
hemicryptophytes (11%) and geophytes (3%). Chorological analysis revealed that Saharo-Arabian (81.8%) constitute the main bulk
of the total flora of the studied area. The majority of the perennial species behave similarly to each other in their phenology, and
usually perennials sprout at the end of February, become leafy in March, flower in April and produce fruits between April and July.
The investigation revealed that the wadis studied are potential shelters of four vegetation groups. Twenty two of the recorded species
(33.3%) are omnipresent and had a dominant degree of occurrence (Q-value < 0.2). The highest among others were Zilla spinosa and
Zygophyllum coccineum which recorded in 86% and 88% respectively of the studied stands and spread their dominancy all over the
Eastern Desert of Egypt.

Abstract
Torrential rains (in January 2011) that have swept a limited area in the Eastern Desert, facing Assiut Province (Upper Egypt),
resulted in enriching the vegetation in Wadi Al-Assiuty and its tributary Wadi Habib. Vegetation survey carried out shortly after this
event (in May) revealed the prevalence of annuals which are hardly recognizable in such usually dry habitats. The normally scarce
perennial vegetation has flourished. A total of 66 plant species, 33 perennials and 33 annuals, belonging to 53 genera from 22 different
families were recorded. Therophytes are the predominant life form (50%) followed by chamaephytes (21%), phanerophytes (15%),
hemicryptophytes (11%) and geophytes (3%). Chorological analysis revealed that Saharo-Arabian (81.8%) constitute the main bulk
of the total flora of the studied area. The majority of the perennial species behave similarly to each other in their phenology, and
usually perennials sprout at the end of February, become leafy in March, flower in April and produce fruits between April and July.
The investigation revealed that the wadis studied are potential shelters of four vegetation groups. Twenty two of the recorded species
(33.3%) are omnipresent and had a dominant degree of occurrence (Q-value < 0.2). The highest among others were Zilla spinosa and
Zygophyllum coccineum which recorded in 86% and 88% respectively of the studied stands and spread their dominancy all over the
Eastern Desert of Egypt.

The binding of ciprofloxacin (CFX) to human serum albumin (HSA) has been investigated by fluorescence displacement and induced circular dichroism (ICD) measurements. Displacement measurements were performed with CFX in the absence and presence of marker ligands (hemin for domain I, bilirubin for interspace of domain IA and IIA, chloroform for domain II, and diazepam for domain III) to establish CFX binding site in one of the three major domains of HSA. The primary binding site of CFX is located in site I of HSA (domain IIA) in close vicinity to the site where chloroform (CHCl3) binds. It is depicted from the decrease in quenching constant of HSA-CHCl3 system (0.02 ± 0.06) × 10-3 L mol-1 compared to HSA-CFX-CHCl3 system (0.01 ± 0.06) × 10-3 L mol-1 as obtained by the fluorescence displacement spectroscopy. Furthermore, far-UV CD results show that the binding of CFX leads to change in the helicity of HSA. The ICD results indicated that the CFX binds to the domain IIA of HSA which is in agreement with the fluorescence displacement results.

Reactions of indole-2,3-dione 1 with 2-mercaptobenzimidazole, o-phenylenediamine, 2-
aminophenol, 2-aminobenzothiazole, 2-aminobenzimidazole and 3-methyl-1-phenyl-2-
pyrazolin-5-one were carried out to give compounds spiroindolethiazetobenzimidazole 2,
spirobenzimidazole(oxazole)indoline 3a,b, benzothiazol(imidazol) iminoindolinone 4a,b
and methyloxoindolylidenepyrazolone 5 respectively. Compound 5 was reacted with 2-
aminophenol as well as o-phenylenediamine to give new spirooxazepine and diazepine
derivatives 6a,b respectively. Reaction of 5 with nitrogen nucleophiles as well as carbon
nucleophiles was investigated to furnish new spiro heterocycles 7-11. The reaction of 2-(2-
oxo-1,2-dihydroindol-3-ylidene)malononitrile compound 12 with 3-methyl-1-phenyl-2-
pyrazoline-5-one was carried out to give spiroindolopyranopyrazolo derivative 13.
Compounds 4a,b was reacted with thioglycolic acid to give thiazolidinone derivatives
14a,b. Epoxidation of 5 using monoperoxyphthalic acid magnesium salt hexahydrate and
hydrogen peroxide were executed to afford the novel dispiro (2-pyrazolin
oxiraneindoline)dione compound 15. The chemical structures of the synthesized compounds
were well established by elemental and spectral analyses.

Reactions of indole-2,3-dione 1 with 2-mercaptobenzimidazole, o-phenylenediamine, 2-
aminophenol, 2-aminobenzothiazole, 2-aminobenzimidazole and 3-methyl-1-phenyl-2-
pyrazolin-5-one were carried out to give compounds spiroindolethiazetobenzimidazole 2,
spirobenzimidazole(oxazole)indoline 3a,b, benzothiazol(imidazol) iminoindolinone 4a,b
and methyloxoindolylidenepyrazolone 5 respectively. Compound 5 was reacted with 2-
aminophenol as well as o-phenylenediamine to give new spirooxazepine and diazepine
derivatives 6a,b respectively. Reaction of 5 with nitrogen nucleophiles as well as carbon
nucleophiles was investigated to furnish new spiro heterocycles 7-11. The reaction of 2-(2-
oxo-1,2-dihydroindol-3-ylidene)malononitrile compound 12 with 3-methyl-1-phenyl-2-
pyrazoline-5-one was carried out to give spiroindolopyranopyrazolo derivative 13.
Compounds 4a,b was reacted with thioglycolic acid to give thiazolidinone derivatives
14a,b. Epoxidation of 5 using monoperoxyphthalic acid magnesium salt hexahydrate and
hydrogen peroxide were executed to afford the novel dispiro (2-pyrazolin
oxiraneindoline)dione compound 15. The chemical structures of the synthesized compounds
were well established by elemental and spectral analyses.