Improvement of Selected Morphological, Physiological, and Biochemical Parameters of Banana (Musa acuminata L.) Using Potassium Silicate under Drought Stress Condition Grown in vitro

Drought stress has become more common in recent years as a result of climate change impacts on the production of banana crops and other fruit trees.The growth and productivity of Musa spp are severely impacted by the gradual degradation of water resources and the erratic distribution pattern of annual precipitation amount.The aim of the work includes increased drought tolerance in light of water scarcity in the world as a result of the bananas’being gluttonous for water needs.This investigation was carried out from 2019 to 2020 to study the effect of potassium silicate on morphological growth and biochemical parameters of Musa acuminata L under drought stress by PEG.As a result,drought stress reduced the morphological characteristics such as shoots number,shoot length,roots number,and survival percentage and biochemical characteristics such as chlorophyll a,b,carotenoids,stomatal status,and RWC.While proline content increased in the leaf of M.acuminata L.Media complemented with K2SiO3(2 to 6 mM)either individually or in combination with PEG led to an improvement in all morphological and biochemical characteristics.The activities of CAT,POD,and PPO enzymes increased significantly compared to control.Furthermore,the lowest PPO,CAT,and POD activity were achieved.Additionally,K2SiO3 treatments under drought stress successfully enhanced the leaf stomatal behavior.Our results suggest that K2SiO3 can help to maintain plant integrity in the tested cultivar under drought stress.

Trichoderma-Induced Improvement in Growth, Photosynthetic Pigments, Proline, and Glutathione Levels in Cucurbita pepo Seedlings under Salt Stress

Salt stress is one of the major abiotic stress in plants.However,traditional approaches are not always efficient in conferring salt tolerance.Experiments were conducted to understand the role of Trichoderma spp.(T.harzianum and T.viride)in growth,chlorophyll(Chl)synthesis,and proline accumulation of C.pepo exposed to salinity stress.There were three salt stress(50,100,and 150 mM NaCl)lavels and three different Trichoderma inoculation viz.T.harzianum,T.viride,and T.harzianum+T.viride.Salt stress significantly declined the growth in terms of the shoot and root lengths;however,it was improved by the inoculation of Trichoderma spp.C.pepo inoculated with Trichoderma exhibited increased synthesis of pigments like chl a,chl b,carotenoids,and anthocyanins under normal conditions.It was interesting to observe that such positive effects were maintained under salt-stressed conditions,as reflected by the amelioration of the salinity-mediated decline in growth,physiology and antioxidant defense.The inoculation of Trichoderma spp.enhanced the synthesis of proline,glutathione,proteins and increased the relative water content.In addition,Trichoderma inoculation increased membrane stability and reduced the generation of hydrogen peroxide.Therefore,Trichoderma spp.can be exploited either individually or in combination to enhance the growth and physiology of C.pepo under saline conditions.

Mycogenic Silver Nanoparticles From Endophytic Trichoderma atroviride with Antimicrobial Activity

There is an increasing interest in developing nanoparticles with diverse biologic activities.To this end,we prepared 10 to 15 nm silver nanoparticles(AgNP)from native isolates of Trichoderma atroviride.Within this study,endophytic fungi hosted four medicinal plants in Saint Katherine Protectorate,South Sinai,Egypt have been isolated by surface sterilization technique on four isolation media.Ten species,based on their frequency of occurrence,out of twenty recovered taxa were tested for their capability to synthesize extracellular AgNPs.Trichoderma atroviride hosted Chiliadenus montanus was found to be the best candidate for the production of mycogenic AgNPs among all examined species.The mycosynthesized AgNPs were compared with chemically synthesized and characterized using Ultraviolet-visible(UV-vis)spectroscopy,Raman spectroscopy,X-ray diffraction(XRD)and high-resolution transmission electron microscopy(HRTEM)techniques.The HRTEM result showed the distribution of spherical AgNPs ranging from 10 to 15 nm.Trichoderma atroviride isolate was subjected to sequencing for confirmation of phenotypic identification.The internal transcribed spacer(ITS)1-5.8 s-ITS2 rDNA sequences obtained were compared with those deposited in the GenBank Database and registered with accession number MH283876 in the NCBI Database.Antibacterial,anticandidal and antifungal effects of chemically and mycosynthesized AgNPs were examined at various concentrations in vitro against six pathogenic bacteria and 4 pathogenic fungi by agar well diffusion technique.Standard antibiotics;Gentamicin,Amoxicillin,Clotrimazole,and Nystatin at 5μg/disk were taken as positive controls,while 5%DMSO was used as the negative control.Our data revealed that the application of mycogenic AgNPs at a concentration of 100 ppm resulted in maximum inhibition of pathogenic bacteria and fungi.These data suggest that AgNPs from native isolates of Trichoderma atroviride(MH283876)offer a source of rapid synthesis of eco-friendly,economical biomaterials that show antimicrobial activities.