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Summary The onset of stomatal closure reduces transpiration during drought. In seed plants, drought causes declines in plant water status which increases leaf endogenous abscisic acid (ABA) levels required for stomatal closure. There are multiple possible points of increased belowground resistance in the soil–plant atmospheric continuum that could decrease leaf water potential enough to trigger ABA production and the subsequent decreases in transpiration.We investigate the dynamic patterns of leaf ABA levels, plant hydraulic conductance and the point of failure in the soil–plant conductance in the highly embolism‐resistant speciesCallitris tuberculatausing continuous dendrometer measurements of leaf water potential during drought.We show that decreases in transpiration and ABA biosynthesis begin before any permanent decreases in predawn water potential, collapse in soil–plant hydraulic pathway and xylem embolism spread.We find that a dynamic but recoverable increases in hydraulic resistance in the soil in close proximity to the roots is the most likely driver of declines in midday leaf water potential needed for ABA biosynthesis and the onset of decreases in transpiration.
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Silencing ZmPP2C‐A10 with a foxtail mosaic virus (FoMV) derived vector benefits maize growth and development following water limitation
Abstract Global climate change is causing more frequent and severe droughts, which can have negative impacts on plant growth and crop productivity. Under drought conditions, plants produce the hormone ABA (abscisic acid), which regulates adaptive responses, such as stomatal closure and root elongation. Plant viruses have been used in the lab to convey new traits to plants and could also be used to increase production of ABA or to enhance downstream plant drought resistance responses.In this study, foxtail mosaic virus (FoMV) was used to silenceZmPP2C‐A10, a negative regulator of ABA signalling, in maize (Zea maysL.). Both silenced and control plants were exposed to an 8‐day drought treatment, followed by a 30‐day period of rewatering, after which indicators of drought resistance were measured.After drought treatment, we observed a nearly twofold increase in expression of a stress‐mitigation gene,ZmRAB17, reduced chlorophyll fluorescence changes (indicator of stress), and increased plant biomass and development in theZmPP2C‐A10‐silenced maize compared to controls.These results demonstrate that the FoMV system can be used to silence endogenous expression ofZmPP2C‐A10and increase maize tolerance to drought. This could offer a useful tool to improve crop traits and reduce yield loss during the growing season.
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- Award ID(s):
- 2026068
- PAR ID:
- 10482030
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Plant Biology
- Volume:
- 25
- Issue:
- 6
- ISSN:
- 1435-8603
- Page Range / eLocation ID:
- 956 to 964
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1111/plb.13568
