Drought is a major environmental factor limiting cotton (Gossypium hirsutum L.) productivity worldwide and projected climate changes could increase their negative effects in the future. Thus, targeting the molecular m...Drought is a major environmental factor limiting cotton (Gossypium hirsutum L.) productivity worldwide and projected climate changes could increase their negative effects in the future. Thus, targeting the molecular mechanisms correlated with drought tolerance without reducing productivity is a challenge for plant breeding. In this way, we evaluated the effects of water deficit progress on AtDREB2A-CA transgenic cotton plant responses, driven by the stress-inducible rd29 promoter. Besides shoot and root morphometric traits, gas exchange and osmotic adjustment analyses were also included. Here, we present how altered root traits shown by transgenic plants impacted on physiological acclimation responses when submitted to severe water stress. The integration of AtDREB2A-CA into the cotton genome increased total root volume, surface area and total root length, without negatively affecting shoot morphometric growth parameters and nor phenotypic evaluated traits. Additionally, when compared to wild-type plants, transgenic plants (17-T0 plants and its progeny) highlighted a gradual pattern of phenotypic plasticity tosome photosynthetic parameters such as photosynthetic rate and stomatal conductance with water deficit progress. Transgene also promoted greater shoot development and root robustness (greater and deeper root mass) allowing roots to grow into deeper soil layers. The same morpho-physiological trend was observed in the subsequent generation (17.6-T2). Our results suggest that the altered root traits shown by transgenic plants are the major contributors to higher tolerance response, allowing the AtDRE2A-CA-cotton plants to maintain elevated stomatal conductance and assimilate rates and, consequently, reducing their metabolic costs involved in the antioxidant responses activation. These results also suggest that these morpho-physiological changes increased the number of reproductive structures retained per plant (26% higher) when compared with its non-transgenic counterpart. This is the first report of cotton plants overexpressing the AtDRE2A-CA transcription factor, demonstrating a morpho-physiological and yield advantages under drought stress, without displaying any yield penalty under irrigated conditions. The mechanisms by which the root traits influenced the acclimation of the transgenic plants to severe water deficit conditions are also discussed. These data present an opportunity to use this strategy in cotton breeding programs in order to improve drought adaptation toward better rooting features.展开更多
Thellungiella salsuginea （formerly T. halophila）, a species closely related to Arabidopsis （Arabidopsis thali-ana）, is tolerant not only to high salt levels, but also to chilling, freezing, and ozone. Here, we rep...Thellungiella salsuginea （formerly T. halophila）, a species closely related to Arabidopsis （Arabidopsis thali-ana）, is tolerant not only to high salt levels, but also to chilling, freezing, and ozone. Here, we report that T. salsuginea also shows greater heat tolerance than Arabidopsis. We identified T. salsuginea HsfAld （TsHsfAld） as a gene that can confer marked heat tolerance on Arabidopsis. TsHsfAld was identified via Full-length cDNA Over-eXpressing gene （FOX） hunt-ing from among a collection of heat-stress-related T. salsuginea cDNAs. Transgenic Arabidopsis overexpressing TsHsfAld showed constitutive up-regulation of many genes in the Arabidopsis AtHsfA1 regulon under normal growth tempera-ture. in Arabidopsis mesophyll protoplasts, TsHsfAld was localized in both the nucleus and the cytoplasm. TsHsfAld also interacted with AtHSP90, which negatively regulates AtHsfAls by forming HsfA1-HSP90 complexes in the cytoplasm. It is likely that the partial nuclear localization of TsHsfAld induced the expression of the AtHsfAld regulon in the transgenic plants at normal temperature. We also discovered that transgenic Arabidopsis plants overexpressing AtHsfAldwere more heat-tolerant than wild-type plants and up-regulated the expression of the HsfAld regulon, as was observed in TsHsfAld-overexpressing plants. We propose that the products of both TsHsfAld and AtHsfAld function as positive regulators of Arabidopsis heat-stress response and would be useful for the improvement of heat-stress tolerance in other plants.展开更多
The global population is expected to increase by 10 billion by 2050,the demand for food and water is also likely to increase.Several factors intensify the growing water scarcity,such as inefficient water use in the fo...The global population is expected to increase by 10 billion by 2050,the demand for food and water is also likely to increase.Several factors intensify the growing water scarcity,such as inefficient water use in the food value chain and inadequate infrastructure to save water.The changing climate also exacerbates the rising temperature by making the drier areas drier and negatively impacting agriculture production in most parts of the world.A decrease in precipitation has been observed in the tropics and sub-tropics,such as the Sahel region of Southern Africa,the Mediterranean,South Asia,and the Southwest of US since 1970(https://www.climatecommunication.org).展开更多
基金supported by grants of funds from the Brazilian government(EMBRAPA,CNPq,CAPES and FAPDF).
文摘Drought is a major environmental factor limiting cotton (Gossypium hirsutum L.) productivity worldwide and projected climate changes could increase their negative effects in the future. Thus, targeting the molecular mechanisms correlated with drought tolerance without reducing productivity is a challenge for plant breeding. In this way, we evaluated the effects of water deficit progress on AtDREB2A-CA transgenic cotton plant responses, driven by the stress-inducible rd29 promoter. Besides shoot and root morphometric traits, gas exchange and osmotic adjustment analyses were also included. Here, we present how altered root traits shown by transgenic plants impacted on physiological acclimation responses when submitted to severe water stress. The integration of AtDREB2A-CA into the cotton genome increased total root volume, surface area and total root length, without negatively affecting shoot morphometric growth parameters and nor phenotypic evaluated traits. Additionally, when compared to wild-type plants, transgenic plants (17-T0 plants and its progeny) highlighted a gradual pattern of phenotypic plasticity tosome photosynthetic parameters such as photosynthetic rate and stomatal conductance with water deficit progress. Transgene also promoted greater shoot development and root robustness (greater and deeper root mass) allowing roots to grow into deeper soil layers. The same morpho-physiological trend was observed in the subsequent generation (17.6-T2). Our results suggest that the altered root traits shown by transgenic plants are the major contributors to higher tolerance response, allowing the AtDRE2A-CA-cotton plants to maintain elevated stomatal conductance and assimilate rates and, consequently, reducing their metabolic costs involved in the antioxidant responses activation. These results also suggest that these morpho-physiological changes increased the number of reproductive structures retained per plant (26% higher) when compared with its non-transgenic counterpart. This is the first report of cotton plants overexpressing the AtDRE2A-CA transcription factor, demonstrating a morpho-physiological and yield advantages under drought stress, without displaying any yield penalty under irrigated conditions. The mechanisms by which the root traits influenced the acclimation of the transgenic plants to severe water deficit conditions are also discussed. These data present an opportunity to use this strategy in cotton breeding programs in order to improve drought adaptation toward better rooting features.
文摘Thellungiella salsuginea （formerly T. halophila）, a species closely related to Arabidopsis （Arabidopsis thali-ana）, is tolerant not only to high salt levels, but also to chilling, freezing, and ozone. Here, we report that T. salsuginea also shows greater heat tolerance than Arabidopsis. We identified T. salsuginea HsfAld （TsHsfAld） as a gene that can confer marked heat tolerance on Arabidopsis. TsHsfAld was identified via Full-length cDNA Over-eXpressing gene （FOX） hunt-ing from among a collection of heat-stress-related T. salsuginea cDNAs. Transgenic Arabidopsis overexpressing TsHsfAld showed constitutive up-regulation of many genes in the Arabidopsis AtHsfA1 regulon under normal growth tempera-ture. in Arabidopsis mesophyll protoplasts, TsHsfAld was localized in both the nucleus and the cytoplasm. TsHsfAld also interacted with AtHSP90, which negatively regulates AtHsfAls by forming HsfA1-HSP90 complexes in the cytoplasm. It is likely that the partial nuclear localization of TsHsfAld induced the expression of the AtHsfAld regulon in the transgenic plants at normal temperature. We also discovered that transgenic Arabidopsis plants overexpressing AtHsfAldwere more heat-tolerant than wild-type plants and up-regulated the expression of the HsfAld regulon, as was observed in TsHsfAld-overexpressing plants. We propose that the products of both TsHsfAld and AtHsfAld function as positive regulators of Arabidopsis heat-stress response and would be useful for the improvement of heat-stress tolerance in other plants.
文摘The global population is expected to increase by 10 billion by 2050,the demand for food and water is also likely to increase.Several factors intensify the growing water scarcity,such as inefficient water use in the food value chain and inadequate infrastructure to save water.The changing climate also exacerbates the rising temperature by making the drier areas drier and negatively impacting agriculture production in most parts of the world.A decrease in precipitation has been observed in the tropics and sub-tropics,such as the Sahel region of Southern Africa,the Mediterranean,South Asia,and the Southwest of US since 1970(https://www.climatecommunication.org).
