Source: PURDUE UNIVERSITY submitted to
WATER-USE EFFICIENCY IN PLANTS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0207287
Grant No.
(N/A)
Project No.
IND011860
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Oct 1, 2006
Project End Date
Sep 30, 2011
Grant Year
(N/A)
Project Director
Mickelbart, M. V.
Recipient Organization
PURDUE UNIVERSITY
(N/A)
WEST LAFAYETTE,IN 47907
Performing Department
HORTICULTURE
Non Technical Summary
Limited supply of water is one of the greatest threats to the widespread, consistent production of food crops. Furthermore, the efficient use of water is already an issue in landscapes in arid climates, such as the southwest of the United States, and will be an increasingly significant problem in areas such as the Midwest, as recent droughts have shown. Water also limits growth of forests, which leads to longer production time in production forests, and reduced carbon uptake in natural forests. Therefore, a greater understanding of how plants maintain growth under water-limited conditions will have a tremendous impact on all sectors of plant production. Water use efficiency is the amount of carbon dioxide assimilated by leaves per unit of water vapor transpired. It constitutes one of the most important traits controlling plant productivity in dry environments. A better understanding of this trait will result in the ability to produce plants (through biotechnology or traditional breeding methods) that are able to remain productive, even with limited water. An important purpose of the project is to understand the role of specific genes in controlling water use efficiency in plants.
Animal Health Component
20%
Research Effort Categories
Basic
80%
Applied
20%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1022410102030%
1112410106015%
2012410108015%
2032410102030%
2062410106010%
Goals / Objectives
The research will elucidate the fundamental molecular, genetic and physiological mechanisms that control the ratio of carbon fixation to water loss (water-use efficiency) in plants. The specific experimental objectives are: (1)Quantify the genetic basis of leaf- and whole-plant water-use efficiency in Arabidopsis and Thelungiella, using loss- and gain-of-function molecular genetic approaches and (2) Develop water delivery strategies to optimize water-use efficiency in perennial plant production.
Project Methods
The research will elucidate the fundamental molecular, genetic and physiological mechanisms that control the ratio of carbon fixation to water loss (water-use efficiency) in plants. We will utilize both loss- and gain-of-function genetic approaches to reveal candidate genes that may control WUE. Two model plants, Arabidopsis thaliana and Thellungiella halophila, will comprise the genetic resources for gene identification. Activation tagging (primarily T-DNA), chemical or fast neutron mutagenesis, or RNA suppression will be used to produce populations for screening/selection of genotypes with altered stress responsiveness. Furthermore, we will utilize the natural variation present in both Arabidopsis and Thellungiella to identify water use efficient phenotypes. We will assess a large collection of Arabidopsis and Thellungiella mutants and ecotypes for WUE by monitoring gas exchange (transpiration and net CO2 assimilation rates) using a multiplexed gas-exchange system. We are in possession of at least 40 confirmed stomatal mutants of Arabidopsis as well as several hundred mutants with altered responsiveness to stress and ABA-induced promoters, including promoters from the following stress controlled genes: rd29A, SULFP, and CHX17P. Candidate alleles with strong effects on WUE will be identified by positional cloning or analysis of genome sequence that flank the insertional tag. Genomic microarray analysis and bioinformatics, second/third-site suppressor/enhancer mutant screening, and molecular interaction strategies will be used to dissect regulatory signal networks necessary for plant growth and development in abiotic stress environments. Eventually, plant biotechnology research will establish if ectopic expression of tolerance traits will enhance water use efficiency of woody plant species.

Progress 10/01/06 to 09/30/11

Outputs
OUTPUTS: In the past year, we have continued our characterization of the transcription factor GTL1 on water use efficiency in Arabidopsis, confirming the role of calmodulin and calcium in its activity. We also characterized the effect of this gene in poplar, an important economic species that is a high user of water. We have also sampled a hybrid mapping population of maize for carbon isotope discrimination and will use this data to identify QTL potentially involved in water use efficiency in this species. PARTICIPANTS: Heather Pence, graduate student, Purdue University Department of Horticulture and Landscape Architecture. Jie Yin, graduate student, Purdue University Department of Horticulture and Landscape Architecture. Chan Yul Yoo, graduate student, Purdue University Department of Horticulture and Landscape Architecture. Mike Hasegawa, Professor, Purdue University Department of Horticulture and Landscape Architecture. Rachel Robinson, graduate student, Purdue University Department of Horticulture TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
New knowledge that has resulted from this work includes: 1) Determination of the role of calcium and calmodulin in the activity of AtGTL1, a transcriptional regulator of water use efficiency in Arabidopsis. 2) Characterization of the genetic variation for water use efficiency in maize.

Publications

  • Mickelbart, M.V., P.M. Hasegawa, and D.E. Salt. 2010. Responses and Adaptations to Abiotic Stress. In: L. Taiz and E. Zeiger (eds.). Plant Physiology, 5th Ed. Sinauer Associates, Inc., Sunderland, Massachusetts.
  • Weng, H., C.Y. Yul, M.J. Gosney, P.M. Hasegawa, and M.V. Mickelbart*. 2011. Poplar GTL1 is a Ca2+/calmodulin-binding transcription factor that functions in plant water use efficiency and drought tolerance. PLoS One (submitted).
  • Yoo, C.Y., P.M. Hasegawa, and M.V. Mickelbart*. 2011. Regulation of stomatal density by the GTL1 transcription factor for improving water use efficiency. Plant Signalling & Behavior 6. IF=2.00 www.landesbioscience.com/journals/10/article/15254/
  • Yoo, C.Y., H.E. Pence, J.B. Jin, K. Miura, M.J. Gosney, P.M. Hasegawa, and M.V. Mickelbart*. 2010. The Arabidopsis GTL1 transcription factor regulates water use efficiency and drought tolerance. The Plant Cell 22:4128-4141. IF=10.68


Progress 10/01/09 to 09/30/10

Outputs
OUTPUTS: In the past year, have have determined the relationship between flowering time and water use in Arabidopsis, carefully characterized the effect of a transcription factor, gtl1, on water use efficiency in Arabidopsis, and we are currently deteremining the genetic variation for water use efficiency in a diverse collection of maize germplasm. This work has resulted in one publication and several in preparation. PARTICIPANTS: Heather Pence, graduate student, Purdue University Department of Horticulture and Landscape Architecture. Jie Yin, graduate student, Purdue University Department of Horticulture and Landscape Architecture. Chan Yul Yoo, graduate student, Purdue University Department of Horticulture and Landscape Architecture. Ray Bressan, Professor, Purdue University Department of Horticulture and Landscape Architecture. Mike Hasegawa, Professor, Purdue University Department of Horticulture and Landscape Architecture. Rachel Robinson, graduate student, Purdue University Department of Horticulture TARGET AUDIENCES: Horticulturists and plant breeders PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
New knowledge that has resulted from this work includes: 1) Identification of a gene that regulates suberin accumulation in roots, leading to reduced transpiration and improved water use efficiency. 2) Identification of several flowering genes that also control water use efficiency. 3) Further characterization of AtGTL1 as a transcriptional regulator of water use efficiency in Arabidopsis. 4) Characterization of the genetic variation for water use efficiency in maize. 5) The identification of differentially expressed genes in Thellungiella halophila that appear to be related to water use efficiency.

Publications

  • Orsini, F., M.P. D'Urzo, G. Inan, S. Serra, D.-H. Oh, M.V. Mickelbart, F. Consiglio, X. Li, J.C. Jeong, D.-J. Yun, H.J. Bohnert, R.A. Bressan, and A. Maggio. 2010. A comparative study of salt tolerance parameters in eleven wild relatives of Arabidopsis thaliana. Journal of Experimental Botany 61:3787-3798.


Progress 10/01/08 to 09/30/09

Outputs
OUTPUTS: In the past year, we used our multiplexed balance system for measuring diurnal transpiration in a number of species, including Arabidopsis thaliana, Thellungiella halophila, Populus species, and a number of herbaceous crop plants. We have also used this system to quantify changes in transpiration due to single gene mutations in Arabidopsis. This work has resulted in one publication and two in preparation. We also screened the maize nested association mapping founder lines for variation in water use efficiency. PARTICIPANTS: PARTICIPANTS: Heather Pence, graduate student, Purdue University Department of Horticulture and Landscape Architecture. Jie Yin, graduate student, Purdue University Department of Horticulture and Landscape Architecture. Chan Yul Yoo, graduate student, Purdue University Department of Horticulture and Landscape Architecture. Ray Bressan, Professor, Purdue University Department of Horticulture and Landscape Architecture. Mike Hasegawa, Professor, Purdue University Department of Horticulture and Landscape Architecture. Robert Heath, Professor (retired), University of California, Riverside, Botany and Plant Sciences Department TARGET AUDIENCES: TARGET AUDIENCES: Target audiences are scientists working in the area of plant water use, growers who can apply the information generated to growing crops (e.g. avocado work with Heath at UC Riverside). PROJECT MODIFICATIONS: PROJECT MODIFICATIONS: We have added maize to our model crops that we are using to understand water use efficiency in plants.

Impacts
New knowledge that has resulted from this work includes: 1) Identification of a gene that regulates suberin accumulation in roots, leading to reduced transpiration and improved water use efficiency. 2) Identification of several flowering genes that also control water use efficiency. 3) Further characterization of AtGTL1 as a transcriptional regulator of water use efficiency in Arabidopsis.

Publications

  • Yoo, C.Y., H.E. Pence, P.M. Hasegawa, and M.V. Mickelbart*. 2009. Regulation of transpiration to improve crop water use. Critical Reviews in Plant Science 28:410-431.
  • Baxter, I.R., P.S. Hosmani, A. Rus, B. Lahner, J. Borevitz, B. Muthukumar, M.V. Mickelbart, L. Schreiber, R.B. Franke, and D.E. Salt*. 2009. Root suberin regulates water relations and mineral nutrition in Arabidopsis. PLoS Genetics 5(5):e1000492. doi:10.1371/journal.pgen.1000492.
  • AbuQamar S., H. Luo, K. Laluk, M. V. Mickelbart and T. Mengiste*. 2009. Crosstalk between biotic and abiotic stress responses in tomato is mediated by the AIM1 transcription factor. The Plant Journal 58:347-360.


Progress 10/01/07 to 09/30/08

Outputs
OUTPUTS: Our work is focused on determining the molecular and physiological basis of water use efficiency (WUE) in plants. In the past year, we have further refined our system for measuring continuous water loss in plants, including the revision of our spreadsheets and analysis. This has allowed a number of users from outside our lab use this equipment for rapid determination of diurnal water loss patterns. Using this system, we have characterized the diurnal water loss patterns of approximately 15 species and genotypes within those species to 1) quantify the variation among species in nighttime water loss and 2) determine the variation within species for this trait. The long term goal is to determine the role of nighttime water loss in overall water use efficiency. Information generated from this project was presented at an international meeting in Amman, Jordan, and will be written up for publication in the coming year. We are also interested in changes in WUE during development and in response to cultural management. PARTICIPANTS: Chan Yul Yoo, graduate student, Purdue University Department of Horticulture and Landscape Architecture. Ray Bressan, Professor, Purdue University Department of Horticulture and Landscape Architecture. Mike Hasegawa, Professor, Purdue University Department of Horticulture and Landscape Architecture. Robert Heath, Professor (retired), University of California, Riverside, Botany and Plant Sciences Department TARGET AUDIENCES: Target audiences are scientists working in the area of plant water use, growers who can apply the information generated to growing crops (e.g. avocado work with Heath at UC Riverside). PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Outcomes to date from this project include a more thorough understanding of the degree and patterns of water loss during the dark period in plants. Nighttime water loss has typically been assumed to be minimal, and therefore not an important aspect of WUE. We have shown, however, that nighttime water loss can account for up to 30% of the total diurnal water loss. Furthermore, we have shown that there is significant variation within species for this trait. Taken together, our data supports the idea that selecting for low nighttime water loss may result in increased WUE. Furthermore, we have determined that patterns of nighttime water loss vary among species, which may give some insight into the mechanisms of water loss regulation in plants. This is new information will be published in the next year and should lead to a change in the perception of the importance of nighttime water loss. Our work also includes applied aspects of WUE. Through a series of experiments, we tested the hypothesis that supplemental sulfur application to ornamental crops would increase stress tolerance and WUE by increasing N use efficiency and allowing for the synthesis of stress-related compounds. Our experiments showed that this was not the case for a number of species.

Publications

  • Mickelbart, M.V.*, S. Larsen, R. Heath, and M.L. Arpaia. 2007. Changes in photosynthesis during flush development in avocado (Persea americana Mill.). HortScience 42(4):992.
  • Mickelbart, M.V.*, N. Wasmer, S. Revankar, and L. Collier-Christian. 2007. Effects of supplemental sulfur on growth of three woody ornamental species. HortScience 42(4):994.
  • Mickelbart M.V., C.Y. Yoo and H.E. Pence. 2008. Water use efficiency: The role of stomatal traits on crop performance. Multinational Agricultural Research and Development (MARD) Scientific Symposium. Frontiers in Agriculture: Abiotic and Biotic Stress in Plants. Amman, Jordan November 3-7, p. 43.


Progress 10/01/06 to 09/30/07

Outputs
OUTPUTS: In the past year, we have refined our multiplexed balance system for accurately measuring diurnal transpiration in a number of species, including Arabidopsis thaliana, Thellungiella halophila, and Populus species. With this system, we have measured significant differences in transpiration rates both in light and dark conditions. We have identified genotypes in all these species that exhibit contrasting water loss patterns and will use these contrasting genotypes to determine the physiological basis for differences in water use efficiency. PARTICIPANTS: Chan Yul Yoo, graduate student, Purdue University Department of Horticulture and Landscape Architecture. Ray Bressan, Professor, Purdue University Department of Horticulture and Landscape Architecture. Mike Hasegawa, Professor, Purdue University Department of Horticulture and Landscape Architecture. Robert Heath, Professor (retired), University of California, Riverside, Botany and Plant Sciences Department TARGET AUDIENCES: Target audiences are scientists working in the area of plant water use, growers who can apply the information generated to growing crops (e.g. avocado work with Heath at UC Riverside). PROJECT MODIFICATIONS: Substantial time was spent refining the multiplexed balance system. This led to less progress than anticipated. The initial problems have been resolved and the system is working very well now.

Impacts
New knowledge that has resulted from this work includes: 1) Identification of various patterns of stomatal opening during dark hours in different genotypes within a species. 2) Data that suggests that vapor pressure deficit has a large effect on water loss at night. 3) Confirmation that the AtGTL1 is a transcriptional regulator of drought tolerance in Arabidopsis.

Publications

  • Yoo, C.Y.*, J.B. Jin, K. Miura, Y. Hua, M. Gosney, M.V. Mickelbart, R.A. Bressan, and P.M. Hasegawa. 2007. Ca2+/CaM signaling through AtGTL1 mediates drought stress adaptation. Plant Physiology, Plant Biology 07, p. 108.
  • Gosney, M.J. and M.V. Mickelbart*. 2006. Measuring water loss in Thellungiella halophila. The Biology of Transpiration: From Guard Cells to Globe, October 10-14, 2006, Snowbird, Utah.
  • Heath, R.L., M.V. Mickelbart*, M.L. Arpaia, C. Fassio, and R. Miller. 2006. Water relations of avocado in response to changes in relative humidity. HortScience 41(4):1058.