Plant secondary metabolites play vital role in plant stress response. In this study we investigated whether root colonization of tomato （Solanum lycopersicum） infected by Trichoderma harzianum leads to alterations i...Plant secondary metabolites play vital role in plant stress response. In this study we investigated whether root colonization of tomato （Solanum lycopersicum） infected by Trichoderma harzianum leads to alterations in the biosynthesis of secondary plant metabolites including phytohormones and osmolyte proline under drought stress. Exposure of tomato to drought caused a drastic decline in plant growth and physiological parameters. Tomato inoculated with T. harzianum showed increased root and shoot growth and chlorophyll pigments as compared to uninoculated controls as well as drought stressed plants. Proline and total soluble protein content was increased in plants inoculated with T. harzianum under both normal as well as drought conditions. An obvious increase in phenol and flavonoid content was observed due to T. haczianum. In addition, T. hat-zianum inoculated plants maintained higher levels of growth regulators indole acetic acid, indole butyric acid, and gibberellic acid under drought stress. Improved secondary metabolites which play an important role in plant stress tolerance by T. hat-zianum may have coordinately worked for bringing the growth regulation by protecting membranes from reactive oxygen species （ROS） and enhance plant growth through accessing more nutrients by root system.展开更多
Endophytic bacteria of halophytic plants play essential roles in salt stress tolerance.Therefore,an understanding of the true nature of plant-microbe interactions under extreme conditions is essential.The current stud...Endophytic bacteria of halophytic plants play essential roles in salt stress tolerance.Therefore,an understanding of the true nature of plant-microbe interactions under extreme conditions is essential.The current study aimed to identify cultivable endophytic bacteria associated with the roots and shoots of Seidlitzia rosmarinus Ehrenb.ex Boiss.grown in the salt-affected soil in Uzbekistan and to evaluate their plant beneficial traits related to plant growth stimulation and stress tolerance.Bacteria were isolated from the roots and the shoots of S.rosmarinus using culture-dependent techniques and identified by the 16S rRNA gene.RFLP(Restriction Fragment Length Polymorphism)analysis was conducted to eliminate similar isolates.Results showed that the isolates from the roots of S.rosmarinus belonged to the genera Rothia,Kocuria,Pseudomonas,Staphylococcus,Paenibacillus and Brevibacterium.The bacterial isolates from the shoots of S.rosmarinus belonged to the genera Staphylococcus,Rothia,Stenotrophomonas,Brevibacterium,Halomonas,Planococcus,Planomicrobium and Pseudomonas,which differed from those of the roots.Notably,Staphylococcus,Rothia and Brevibacterium were detected in both roots and shoots,indicating possible migration of some species from roots to shoots.The root-associated bacteria showed higher levels of IAA(indole-3-acetic acid)synthesis compared with those isolated from the shoots,as well as the higher production of ACC(1-aminocyclopropane-1-carboxylate)deaminase.Our findings suggest that halophytic plants are valuable sources for the selection of microbes with a potential to improve plant fitness under saline soils.展开更多
The biodegradability of chars derived from pyrolysis and hydrothermal carbonisation(HTC) was studied in short-term dynamic incubation experiments under controlled conditions. Carbon dioxide C(CO2) emissions from soil-...The biodegradability of chars derived from pyrolysis and hydrothermal carbonisation(HTC) was studied in short-term dynamic incubation experiments under controlled conditions. Carbon dioxide C(CO2) emissions from soil-char mixtures in combination with solid digestate or mineral nitrogen(N) fertiliser were measured in dynamic chambers for 10 d. Compared to the original material(maize straw), pyrolysis and HTC chars showed significantly lower CO2 emissions and slower decay dynamics; and compared to the soil control, HTC char increased soil respiration to a significant extent, while pyrolysis char did not. The addition of mineral N resulted in a delayed respiration dynamics for HTC char, while the addition of digestate resulted in an increase in the respired CO2 for pyrolysis char and a decrease for HTC char. For the first time, a peculiar two-stage decay kinetics was observed for HTC char,indicating a highly inhomogeneous substrate consisting at least of two C pools.展开更多
基金the Deanship of Scientific Research at King Saud University,Saudi Arabia(RGP-271)
文摘Plant secondary metabolites play vital role in plant stress response. In this study we investigated whether root colonization of tomato （Solanum lycopersicum） infected by Trichoderma harzianum leads to alterations in the biosynthesis of secondary plant metabolites including phytohormones and osmolyte proline under drought stress. Exposure of tomato to drought caused a drastic decline in plant growth and physiological parameters. Tomato inoculated with T. harzianum showed increased root and shoot growth and chlorophyll pigments as compared to uninoculated controls as well as drought stressed plants. Proline and total soluble protein content was increased in plants inoculated with T. harzianum under both normal as well as drought conditions. An obvious increase in phenol and flavonoid content was observed due to T. haczianum. In addition, T. hat-zianum inoculated plants maintained higher levels of growth regulators indole acetic acid, indole butyric acid, and gibberellic acid under drought stress. Improved secondary metabolites which play an important role in plant stress tolerance by T. hat-zianum may have coordinately worked for bringing the growth regulation by protecting membranes from reactive oxygen species （ROS） and enhance plant growth through accessing more nutrients by root system.
基金the Eurasia Program of the Norwegian Centre for Cooperation in Education(CPEA-LT-2016/10095)the German Academic Exchange Service(DAAD)the President's International Fellowship Initiative of the Chinese Academy of Sciences(2018VBA002S).
文摘Endophytic bacteria of halophytic plants play essential roles in salt stress tolerance.Therefore,an understanding of the true nature of plant-microbe interactions under extreme conditions is essential.The current study aimed to identify cultivable endophytic bacteria associated with the roots and shoots of Seidlitzia rosmarinus Ehrenb.ex Boiss.grown in the salt-affected soil in Uzbekistan and to evaluate their plant beneficial traits related to plant growth stimulation and stress tolerance.Bacteria were isolated from the roots and the shoots of S.rosmarinus using culture-dependent techniques and identified by the 16S rRNA gene.RFLP(Restriction Fragment Length Polymorphism)analysis was conducted to eliminate similar isolates.Results showed that the isolates from the roots of S.rosmarinus belonged to the genera Rothia,Kocuria,Pseudomonas,Staphylococcus,Paenibacillus and Brevibacterium.The bacterial isolates from the shoots of S.rosmarinus belonged to the genera Staphylococcus,Rothia,Stenotrophomonas,Brevibacterium,Halomonas,Planococcus,Planomicrobium and Pseudomonas,which differed from those of the roots.Notably,Staphylococcus,Rothia and Brevibacterium were detected in both roots and shoots,indicating possible migration of some species from roots to shoots.The root-associated bacteria showed higher levels of IAA(indole-3-acetic acid)synthesis compared with those isolated from the shoots,as well as the higher production of ACC(1-aminocyclopropane-1-carboxylate)deaminase.Our findings suggest that halophytic plants are valuable sources for the selection of microbes with a potential to improve plant fitness under saline soils.
基金performed within the framework of the SAW project "Biochar in Agriculture:Perspectives for Germany and Malaysia" funded by the Leibniz Association,Germany,within the context of the "Joint Initiative for Research and Innovation"
文摘The biodegradability of chars derived from pyrolysis and hydrothermal carbonisation(HTC) was studied in short-term dynamic incubation experiments under controlled conditions. Carbon dioxide C(CO2) emissions from soil-char mixtures in combination with solid digestate or mineral nitrogen(N) fertiliser were measured in dynamic chambers for 10 d. Compared to the original material(maize straw), pyrolysis and HTC chars showed significantly lower CO2 emissions and slower decay dynamics; and compared to the soil control, HTC char increased soil respiration to a significant extent, while pyrolysis char did not. The addition of mineral N resulted in a delayed respiration dynamics for HTC char, while the addition of digestate resulted in an increase in the respired CO2 for pyrolysis char and a decrease for HTC char. For the first time, a peculiar two-stage decay kinetics was observed for HTC char,indicating a highly inhomogeneous substrate consisting at least of two C pools.
