Root hydraulic conductivity (Lp(r)) and aquaporin amounts change diurnally. Previously, these changes were considered to be spontaneously driven by a circadian rhythm. Here, we evaluated the new hypothesis that diurnal changes could be triggered and enhanced by transpirational demand from shoots. When rice plants were grown under a 12h light/12h dark regime, Lp(r) was low in the dark and high in the light period. Root aquaporin mRNA levels also changed diurnally, but the amplitudes differed among aquaporin isoforms. Aquaporins, such as OsPIP2;1, showed moderate changes, whereas root-specific aquaporins, such as OsPIP2;5, showed temporal and dramatic induction around 2h after light initiation. When darkness was extended for 12h after the usual dark period, no such induction was observed. Furthermore, plants under 100% relative humidity (RH) showed no induction even in the presence of light. These results suggest that transpirational demand triggers a dramatic increase in gene expressions such as OsPIP2;5. Immunocytochemistry showed that OsPIP2;5 accumulated on the proximal end of the endodermis and of the cell surface around xylem. The strong induction by transpirational demand and the polar localization suggest that OsPIP2;5 contributes to fine adjustment of radial water transport in roots to sustain high Lp(r) during the day.
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http://dx.doi.org/10.1111/j.1365-3040.2011.02313.x | DOI Listing |
Plant Biol (Stuttg)
January 2025
Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun, China.
Assessing how dominant peatland species, such as Dasiphora fruticosa, adapt to water table decline is crucial to advance understanding of their growth and survival strategies. Currently, most studies have primarily focused on their growth and biomass, with limited knowledge on the response of non-structural carbohydrates (NSCs) and physiological adaptations of these woody plants under long-term drainage. This study assessed the response of photosynthesis and transpiration rates, biomass, and NSC concentrations (including soluble sugars and starch) in the leaves, stems, and roots of D.
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December 2024
Department of Public Health, School of Healthcare Sciences, Sefako Makgatho Health Sciences University, Ga‑Rankuwa, Pretoria 0208, South Africa.
In 2014, the Faculty of Health Sciences at Walter Sisulu University introduced a 20‑week long integrated longitudinal clinical clerkship (ILCC) rotation block as part of its commitment to community‑based education and social responsiveness, with the goal of ensuring that the curriculum is updated to align with the contemporary health system challenges in South Africa. To explore whether medical student participants underwent social and personal transformative learning in understanding complex societal health needs during their integrated longitudinal community clerkship program. This was an exploratory qualitative research study conducted among 113 5 year medical students based at 8 selected hospitals during their 20‑week‑long community clerkship.
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January 2025
CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China.
Both mistletoes and their hosts are challenged by increasing drought, highlighting the necessity of understanding their comparative hydraulic properties. The high transpiration of mistletoes requires efficient water transport, while high xylem tensions demand strong embolism resistance, representing a hydraulic paradox. This study, conducted across four environments with different aridity indices in Yunnan, China, examined the xylem traits of 119 mistletoe-host species pairs.
View Article and Find Full Text PDFBMC Plant Biol
November 2024
Department of Botany, Ecology and Plant Physiology, Universidad de La Laguna (ULL), La Laguna, Canary Islands, 38200, Spain.
Background: Accurate leaf water potential (Ψ) determination is crucial in studying plant responses to water deficit. After excision, water potential decreases, even under low evaporative demand conditions, which has been recently attributed to the equilibration of pre-excision Ψ gradients across the leaf. We assessed the influence of potential re-equilibration on water potential determination by monitoring leaf Ψ and relative water content decline after excision using different storage methods.
View Article and Find Full Text PDFFront Plant Sci
October 2024
Shanxi Agricultural University, Taiyuan, China.
Drought poses a significant challenge to global crop productivity, necessitating innovative approaches to bolster plant resilience. Leveraging transgenic technology to bolster drought tolerance in crops emerges as a promising strategy for addressing the demands of a rapidly growing global populace. AtZAT10/STZ1, a C2H2-type zinc finger protein transcription factor has shown to significantly improve Arabidopsis' tolerance to various abiotic stresses.
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