Project description:The response to moderate and heavy drought of two Solanum tuberosum ssp. Andigena varieties, Sullu (NP 03.03) and SA 2563 (NP 03.01), planted in rain- and soil water protected fields in the Peruvian highlands are compared. Previous experiments indicate that Sullu has a greater capacity for yield maintenance under drought than SA 2563. Both clones have similar morphological properties, vegetative periods and rooting depths, so it can be assumed that the cause for increased drought tolerance of clone NP 03.03 is rather due to physiological or biochemical mechanisms, than to drought escape by deep rooting or earliness. Sullu and SA 2563 were planted in a random block design with 5 plants per bloc and 7 repetitions per treatment. Treatments: (1) drought stress, (2) irrigated control The plants were drip-irrigated in both treatments until tuberization (until day 84 after planting). Subsequently, the irrigation was stopped in the drought field, but continued in the control field. The soil moisture content in the control field was kept near field capacity. Planting date: October 05 2004 Start of drought treatment (during tuberization, 84 days after planting): December 28 2004 First sampling (soil water potential: -0.3 mPa 114 days after planting): January 27 2005 Second sampling (soil water potential –0.6 MPa, 134 days after planting): February 15 2005 Harvest: March 19 2005 (165 days after planting) The experimental design includes gene expression analysis in leaves, roots and stolons at two time points, when soil water potential reaches -0.3 and –0.6 MPa. Gene expression changes will be set in relation with physiological and agronomical data obtained in the same experiment. Keywords: Direct comparison
Project description:The response to moderate and heavy drought of two Solanum tuberosum ssp. Andigena varieties, Sullu (NP 03.03) and SA 2563 (NP 03.01), planted in rain- and soil water protected fields in the Peruvian highlands are compared. Previous experiments indicate that Sullu has a greater capacity for yield maintenance under drought than SA 2563. Both clones have similar morphological properties, vegetative periods and rooting depths, so it can be assumed that the cause for increased drought tolerance of clone NP 03.03 is rather due to physiological or biochemical mechanisms, than to drought escape by deep rooting or earliness. Sullu and SA 2563 were planted in a random block design with 5 plants per bloc and 7 repetitions per treatment. Treatments: (1) drought stress, (2) irrigated control The plants were drip-irrigated in both treatments until tuberization (until day 84 after planting). Subsequently, the irrigation was stopped in the drought field, but continued in the control field. The soil moisture content in the control field was kept near field capacity. Planting date: October 05 2004 Start of drought treatment (during tuberization, 84 days after planting): December 28 2004 First sampling (soil water potential: -0.3 mPa 114 days after planting): January 27 2005 Second sampling (soil water potential –0.6 MPa, 134 days after planting): February 15 2005 Harvest: March 19 2005 (165 days after planting) The experimental design includes gene expression analysis in leaves, roots and stolons at two time points, when soil water potential reaches -0.3 and –0.6 MPa. Gene expression changes will be set in relation with physiological and agronomical data obtained in the same experiment. Keywords: Direct comparison 19 hybs total
Project description:In this series of experiments, we wanted to study the transcriptional responses of plants to different levels of water limitation. For mild drought stress, we controlled water potential (a scientific concept for dryness of soil) by using an automated watering system. This system adds water to soil based on the pF values reported by a pF sensor in soil. pF is a classical and widely used index of water potential that was first defined by Schofield (1935). For severe stress conditions, we withheld watering or even dried plants on a lab bench. Here, the transcriptional profiles were compared between well-watered and Sds-treated rice seedling shoot basal region.<br>Sds (Severe dehydration stress in soil containers): We designated Sds as a term that means a severe drought stress causing dehydration of plants in our experiments (The plants were dehydrated at the sampling point). The drought stress was achieved by withholding water from plants grown in soil containers.
Project description:In this series of experiments, we wanted to study the transcriptional responses of plants to different levels of water limitation. For mild drought stress, we controlled water potential (a scientific concept for dryness of soil) by using an automated watering system. This system adds water to soil based on the pF values reported by a pF sensor in soil. pF is a classical and widely used index of water potential that was first defined by Schofield (1935). For severe stress conditions, we withheld watering or even dried plants on a lab bench. Here, the transcriptional profiles were compared between well-watered and Sds-treated rice seedling shoots.<br>Sds (Severe dehydration stress in soil containers): We designated Sds as a term that means a severe drought stress causing dehydration of plants in our experiments (The plants were dehydrated at the sampling point). The drought stress was achieved by withholding water from plants grown in soil containers.
Project description:In this series of experiments, we wanted to study the transcriptional responses of plants to different levels of water limitation. For mild drought stress, we controlled water potential (a scientific concept for dryness of soil) by using an automated watering system. This system adds water to soil based on the pF values reported by a pF sensor in soil. pF is a classical and widely used index of water potential that was first defined by Schofield (1935). For severe stress conditions, we withheld watering or even dried plants on a lab bench. Here, the transcriptional profiles were compared between well-watered and Md2-treated rice seedling shoots.<br>Md2 (Mild drought level 2): We designated Md2 as a term that means the level of drought severity corresponding to pF2.5, which is equal to a soil matric potential of -31.0 kPa. pF2.5: The value of pF shows the soil matric potential of -31.0 kPa. pF is an index that is equivalent to the effort required for plant root systems to extract water stored in soil.
Project description:In this series of experiments, we wanted to study the transcriptional responses of plants to different levels of water limitation. For mild drought stress, we controlled water potential (a scientific concept for dryness of soil) by using an automated watering system. This system adds water to soil based on the pF values reported by a pF sensor in soil. pF is a classical and widely used index of water potential that was first defined by Schofield (1935). For severe stress conditions, we withheld watering or even dried plants on a lab bench. Here, the transcriptional profiles were compared between well-watered and Md2-treated rice seedling shoot basal region.<br>Md2 (Mild drought level 2): We designated Md2 as a term that means the level of drought severity corresponding to pF2.5, which is equal to a soil matric potential of -31.0 kPa. pF2.5: The value of pF shows the soil matric potential of -31.0 kPa. pF is an index that is equivalent to the effort required for plant root systems to extract water stored in soil.
Project description:Identifying the genetic basis for natural selection is a fundamental research goal, and particularly significant for soil fungi because of their central role in ecosystem functioning. Here, we identify rapid evolutionary processes in the plant root colonizing insect pathogen Metarhizium robertsii. While adapting to a new soil community, expression of TATA box containing cell wall and stress response genes evolved at an accelerated rate, whereas virulence determinants, transposons and chromosome structure were unaltered. The survival of diversified field isolates was increased, confirming that the mutations were adaptive, and we further show that large populations of Metarhizium are principally maintained by associations with plant roots rather than insect populations. These results provide a mechanistic basis for understanding mutational and selective effects on soil microbes.