Background:Cotton(Gossypium hirsutum) provides the largest natural fiber for the textile manufacturing industries,but its production is on the decline due to the effects of salinity.Soil salt-alkalization leads to dam...Background:Cotton(Gossypium hirsutum) provides the largest natural fiber for the textile manufacturing industries,but its production is on the decline due to the effects of salinity.Soil salt-alkalization leads to damage in cotton growth and a decrease in yields.Hyperosmolality-gated calcium-permeable channels(OSCA) have been found to be involved in the detection of extracellular changes which trigger an increase in cytosolic free calcium concentration.Hyperosmolality-induced calcium ion increases have been widely speculated to be playing a role in osmosensing in plants.However,the molecular nature of the corresponding calcium ion channels remains unclearly.In this research work,we describe the OSCA genes and their putative function in osmosensing in plants by carrying out genomewide identification,characterization and functional analysis of the significantly up-regulated OSCA gene,GhOSCA1.1 through reverse genetics.Result:A total of 35,21 and 22 OSCA genes were identified in G.hirsutum,G.arboreum,and G.raimondii genomes,respectively,and were classified into four different clades according to their gene structure and phylogenetic relationship.Gene and protein structure analysis indicated that 35 GhOSCA genes contained a conserved RSN17 TM(PF02714) domain.Moreover,the cis-regulatory element analysis indicated that the OSCA genes were involved in response to abiotic stress.Furthermore,the knockdown of one of the highly up-regulated genes,GhOSCA1.1 showed that the virus-induced gene silenced(VIGS) plants were highly sensitive to dehydration and salinity stresses compared with the none VIGS plants as evident with higher concentration levels of oxidant enzymes compared with the antioxidant enzymes on the leaves of the stressed plants.Conclusion:This study provides the first systematic analysis of the OSCA gene family and will be important for understanding the putative functions of the proteins encoded by the OSCA genes in cotton.These results provide a new insight of defense responses in general and lay the foundatio展开更多
Ex-situ cultivation of biological soil crusts （biocrusts） is a promising technology to produce materials that can induce the recovery of biocrusts in the field for the purposes of preventing soil erosion and improvi...Ex-situ cultivation of biological soil crusts （biocrusts） is a promising technology to produce materials that can induce the recovery of biocrusts in the field for the purposes of preventing soil erosion and improving hydrological function in degraded ecosystems. However, the ability of artificially cultivated biocrusts to survive under adverse field conditions, including drought and heat stresses, is still relatively unknown. Mosses can bolster biocrust resistance to the stresses （e.g., drought and heat） and the resistance may be introduced prior to field cultivation. In this study, we subjected the well-developed artificial moss biocrusts （dominant species of Didjmodon vinealis （Brid.） Zand.） that we cultivated in the phytotron to a dehydration-rehydration experiment and also a heat stress experiment and measured the activities of protective enzymes （including peroxidase （POD）, superoxide dismutase （SOD）, and catalase （CAT）） and the contents of osmoregulatory substances （including soluble proteins and soluble sugars） and malondialdehyde （MDA, an indicator of oxidative stress） in the stem and leaf fragments of mosses. The results showed that, during the dehydration process, the activities of protective enzymes and the contents of osmoregulatory substances and MDA gradually increased with increasing duration of drought stress （over 13 days）. During the rehydration process, values of these parameters decreased rapidly after 1 d of rehydration. The values then showed a gradual decrease for 5 days, approaching to the control levels. Under heat stress （45℃）, the activities of protective enzymes and the content of soluble proteins increased rapidly within 2 h of heat exposure and then decreased gradually with increasing duration of heat exposure. In contrast, the contents of soluble sugars and MDA always increased gradually with increasing duration of heat exposure. This study indicates that artificial moss biocrusts possess a strong drought resistance and this resista展开更多
Macroalgae that inhabit intertidal zones are exposed to the air for several hours during low tide and must endure desiccation and high variations in temperature, light intensity, and salinity. Pyropia yezoensis (Rhodo...Macroalgae that inhabit intertidal zones are exposed to the air for several hours during low tide and must endure desiccation and high variations in temperature, light intensity, and salinity. Pyropia yezoensis (Rhodophyta, Bangiales), a typical intertidal red macroalga that is commercially cultivated in the northwestern Pacific Ocean, was investigated under different dehydration stresses of desiccation, high salinity, and high mannitol concentration. Using chlorophyll fluorescence imaging, photosynthetic activities of P. yezoensis thalli were analyzed using six parameters derived from quenching curves and rapid light curves. A distinct discrepancy was revealed in photosynthetic responses to different dehydration stresses. Dehydration caused by exposure to air resulted in rapid decreases in photosynthetic activities, which were always lower than two other stresses at the same water loss (WL) level. High salinity only reduced photosynthesis significantly at its maximum WL of 40% but maintained a relatively stable maximum quantum yield of photosystem II (PSII) (Fv/Fm). High mannitol concentration induced maximum WL of 20% for a longer time (60 min) than the other two treatments and caused no adverse influences on the six parameters at different WL except for a significant decrease in non-photochemical quenching (NPQ) at 20% WL. Illustrated by chlorophyll fluorescence images, severe spatial heterogeneities were induced by desiccation with lower values in the upper parts than the middle or basal parts of the thalli. The NPQ and rETRmax (maximum relative electron transport rate) demonstrated clear distinctions for evaluating photosynthetic responses, indicating their sensitivity and applicability. The findings of this study indicated that the natural dehydration of exposure to air results in stronger and more heterogeneous effects than those of high salinity or high mannitol concentration.展开更多
基金funded by the National Natural Science Foundation of China(31530053/31621005)the National Key R&D Program(2016YFD0101401/2017YFD0101601)
文摘Background:Cotton(Gossypium hirsutum) provides the largest natural fiber for the textile manufacturing industries,but its production is on the decline due to the effects of salinity.Soil salt-alkalization leads to damage in cotton growth and a decrease in yields.Hyperosmolality-gated calcium-permeable channels(OSCA) have been found to be involved in the detection of extracellular changes which trigger an increase in cytosolic free calcium concentration.Hyperosmolality-induced calcium ion increases have been widely speculated to be playing a role in osmosensing in plants.However,the molecular nature of the corresponding calcium ion channels remains unclearly.In this research work,we describe the OSCA genes and their putative function in osmosensing in plants by carrying out genomewide identification,characterization and functional analysis of the significantly up-regulated OSCA gene,GhOSCA1.1 through reverse genetics.Result:A total of 35,21 and 22 OSCA genes were identified in G.hirsutum,G.arboreum,and G.raimondii genomes,respectively,and were classified into four different clades according to their gene structure and phylogenetic relationship.Gene and protein structure analysis indicated that 35 GhOSCA genes contained a conserved RSN17 TM(PF02714) domain.Moreover,the cis-regulatory element analysis indicated that the OSCA genes were involved in response to abiotic stress.Furthermore,the knockdown of one of the highly up-regulated genes,GhOSCA1.1 showed that the virus-induced gene silenced(VIGS) plants were highly sensitive to dehydration and salinity stresses compared with the none VIGS plants as evident with higher concentration levels of oxidant enzymes compared with the antioxidant enzymes on the leaves of the stressed plants.Conclusion:This study provides the first systematic analysis of the OSCA gene family and will be important for understanding the putative functions of the proteins encoded by the OSCA genes in cotton.These results provide a new insight of defense responses in general and lay the foundatio
基金supported by the National Natural Science Foundation of China(41541008,41671276)the Chinese Universities Scientific Fund(2014YQ006)+1 种基金the West Light Foundation of the Chinese Academy of Sciences(2014-91)the Natural Science Foundation of Qinghai Province(2016-ZJ-943Q)
文摘Ex-situ cultivation of biological soil crusts （biocrusts） is a promising technology to produce materials that can induce the recovery of biocrusts in the field for the purposes of preventing soil erosion and improving hydrological function in degraded ecosystems. However, the ability of artificially cultivated biocrusts to survive under adverse field conditions, including drought and heat stresses, is still relatively unknown. Mosses can bolster biocrust resistance to the stresses （e.g., drought and heat） and the resistance may be introduced prior to field cultivation. In this study, we subjected the well-developed artificial moss biocrusts （dominant species of Didjmodon vinealis （Brid.） Zand.） that we cultivated in the phytotron to a dehydration-rehydration experiment and also a heat stress experiment and measured the activities of protective enzymes （including peroxidase （POD）, superoxide dismutase （SOD）, and catalase （CAT）） and the contents of osmoregulatory substances （including soluble proteins and soluble sugars） and malondialdehyde （MDA, an indicator of oxidative stress） in the stem and leaf fragments of mosses. The results showed that, during the dehydration process, the activities of protective enzymes and the contents of osmoregulatory substances and MDA gradually increased with increasing duration of drought stress （over 13 days）. During the rehydration process, values of these parameters decreased rapidly after 1 d of rehydration. The values then showed a gradual decrease for 5 days, approaching to the control levels. Under heat stress （45℃）, the activities of protective enzymes and the content of soluble proteins increased rapidly within 2 h of heat exposure and then decreased gradually with increasing duration of heat exposure. In contrast, the contents of soluble sugars and MDA always increased gradually with increasing duration of heat exposure. This study indicates that artificial moss biocrusts possess a strong drought resistance and this resista
基金supported by National Key R&D Program of China(2018YFC1406704 and 2020YFD0900702).
文摘Macroalgae that inhabit intertidal zones are exposed to the air for several hours during low tide and must endure desiccation and high variations in temperature, light intensity, and salinity. Pyropia yezoensis (Rhodophyta, Bangiales), a typical intertidal red macroalga that is commercially cultivated in the northwestern Pacific Ocean, was investigated under different dehydration stresses of desiccation, high salinity, and high mannitol concentration. Using chlorophyll fluorescence imaging, photosynthetic activities of P. yezoensis thalli were analyzed using six parameters derived from quenching curves and rapid light curves. A distinct discrepancy was revealed in photosynthetic responses to different dehydration stresses. Dehydration caused by exposure to air resulted in rapid decreases in photosynthetic activities, which were always lower than two other stresses at the same water loss (WL) level. High salinity only reduced photosynthesis significantly at its maximum WL of 40% but maintained a relatively stable maximum quantum yield of photosystem II (PSII) (Fv/Fm). High mannitol concentration induced maximum WL of 20% for a longer time (60 min) than the other two treatments and caused no adverse influences on the six parameters at different WL except for a significant decrease in non-photochemical quenching (NPQ) at 20% WL. Illustrated by chlorophyll fluorescence images, severe spatial heterogeneities were induced by desiccation with lower values in the upper parts than the middle or basal parts of the thalli. The NPQ and rETRmax (maximum relative electron transport rate) demonstrated clear distinctions for evaluating photosynthetic responses, indicating their sensitivity and applicability. The findings of this study indicated that the natural dehydration of exposure to air results in stronger and more heterogeneous effects than those of high salinity or high mannitol concentration.
