The present contribution analyses the Smart City Mission launched in the year 2015 in India from an institutional perspective and examines how it is mobilized for coordinated action. Relying on ...theoretical guidance provided by Ostrom's (2005) ‘Institutional Analysis and Development’ (IAD) framework and González-Arellano's (2022) and Scott's (2008) formulation of ‘Institutional Construction of Futures of Cities’, we analyse a corpus of empirical data to suggest that SC has historical precedents in the way it is institutionalized. Further, to substantiate our findings, a structured literature review of empirical contributions (34 nos.) within the SCOPUS database is undertaken. In conceptual terms, the anticipatory praxis of Smart City Mission leverages the institutional structure of doing flagship programmes and a cultural-cognitive affirmation of neutrality in data-driven governance. The initiative blurs the political city as the action arenas of structuring SC initiatives at the local levels lack operational rules to construct desired outcomes. The paper argues for a need to make the action-to-outcome linkage legible and endow agency to participants to act and control the outcomes by framing collective choice rules. Strengthening action arenas at the city level emboldens the capacity to envision collaborative futures and bridge the gap between anticipation and experience.
•The flagship architecture inscribes longstanding socio-spatial inequalities and constrains the collective agency•Smart City Mission blurs the political city at the local levels due to lack of action-outcome linkages•Disproportionate power is vested with the process holders (bureaucrats/consultants) to delineate Smart City outcomes•Smart City Mission valorizes neoliberal ethos and a strong centralized state.
The paper analyses the visioning of the Greater Mumbai-2034 Development Plan (DP-2034) and its content. Our results suggest that visioning practice is essentially a discursive intervention embedded ...in interpretive struggles. The paper outlines the role of two key planning instruments, Floor Space Index-FSI and No Development Zone-NDZ, which materialised as discursive elements while Mumbai’s urban vision along a de-regulated and market-determined rationale is formulated. Also, to uphold its core view, the Municipal Corporation of Greater Mumbai (civic body) exercised its discursive agency through various strategic practices that revolve around framing, rationalisation, scientification efforts and re-designating territorial boundaries. Simultaneously, visioning created a strategic impulse amongst citizens and civil society actors to realise their agency for change, alter their discursive power and emerge as a stronger discursive agent through forming alliances, engaging in independent surveys, imparting planning literacy, peer learning, shadow visioning and canvassing with media. As a result, MCGM was forced to alter its proposals partially. The empirical case argues that visioning exercises present novel openings for actors to negotiate their pre-given subject position, demand participatory forms of urban governance and acquire discursive agency to exercise the right to change.
Chenopodium quinoa is a halophytic pseudocereal crop that is being cultivated in an ever-growing number of countries. Because quinoa is highly resistant to multiple abiotic stresses and its seed has ...a better nutritional value than any other major cereals, it is regarded as a future crop to ensure global food security. We generated a high-qual- ity genome draft using an inbred line of the quinoa cultivar Real. The quinoa genome experienced one recent genome duplication about 4.3 million years ago, likely reflecting the genome fusion of two Chenopodium parents, in addition to the y paleohexaploidization reported for most eudicots. The genome is highly repetitive （64.5% repeat content） and contains 54 438 protein-coding genes and 192 microRNA genes, with more than 99.3% having orthologons genes from glycophylic species. Stress tolerance in quinoa is associated with the expansion of genes involved in ion and nu- trient transport, ABA homeostasis and signaling, and enhanced basal-level ABA responses. Epidermal salt bladder ceils exhibit similar characteristics as trichomes, with a significantly higher expression of genes related to energy import and ABA biosynthesis compared with the leaf lamina. The quinoa genome sequence provides insights into its exceptional nutritional value and the evolution of halophytes, enabling the identification of genes involved in salinity tolerance, and providing the basis for molecular breeding in quinoa.
Stomata are pores on the leaf surface, bounded by two guard cells, which control the uptake of CO2 for photosynthesis and the concomitant loss of water vapor. In 1898, Francis Darwin 1 showed that ...stomata close in response to reduced atmospheric relative humidity (rh); however, our understanding of the signaling pathway responsible for coupling changes in rh to alterations in stomatal aperture is fragmentary. The results presented here highlight the primacy of abscisic acid (ABA) in the stomatal response to drying air. We show that guard cells possess the entire ABA biosynthesis pathway and that it appears upregulated by positive feedback by ABA. When wild-type Arabidopsis and the ABA-deficient mutant aba3-1 were exposed to reductions in rh, the aba3-1 mutant wilted, whereas the wild-type did not. However, when aba3-1 plants, in which ABA synthesis had been specifically rescued in guard cells, were challenged with dry air, they did not wilt. These data indicate that guard cell-autonomous ABA synthesis is required for and is sufficient for stomatal closure in response to low rh. Guard cell-autonomous ABA synthesis allows the plant to tailor leaf gas exchange exquisitely to suit the prevailing environmental conditions.
► Stomatal closure by reduced atmospheric relative humidity (rh) requires ABA ► Guard cell-autonomous ABA synthesis is required for rh-induced stomatal closure ► Guard cells operate the entire ABA biosynthesis pathway
In response to drought stress the phytohormone ABA (abscisic acid) induces stomatal closure and, therein, activates guard cell anion channels in a calcium-dependent as well as-independent manner. Two ...key components of the ABA signaling pathway are the protein kinase OST1 (open stomata 1) and the protein phosphatase ABI1 (ABA insensitive 1). The recently identified guard cell anion channel SLAC1 appeared to be the key ion channel in this signaling pathway but remained electrically silent when expressed heterologously. Using split YFP assays, we identified OST1 as an interaction partner of SLAC1 and ABI1. Upon coexpression of SLAC1 with OST1 in Xenopus oocytes, SLAC1-related anion currents appeared similar to those observed in guard cells. Integration of ABI1 into the SLAC1/OST1 complex, however, prevented SLAC1 activation. Our studies demonstrate that SLAC1 represents the slow, deactivating, weak voltage-dependent anion channel of guard cells controlled by phosphorylation/dephosphorylation.
Soil salinity is destroying arable land and is considered to be one of the major threats to global food security in the 21st century. Therefore, the ability of naturally salt-tolerant halophyte ...plants to sequester large quantities of salt in external structures, such as epidermal bladder cells (EBCs), is of great interest. Using Chenopodium quinoa, a pseudo-cereal halophyte of great economic potential, we have shown previously that, upon removal of salt bladders, quinoa becomes salt sensitive. In this work, we analyzed the molecular mechanism underlying the unique salt dumping capabilities of bladder cells in quinoa. The transporters differentially expressed in the EBC transcriptome and functional electrophysiological testing of key EBC transporters in Xenopus oocytes revealed that loading of Na+ and Cl− into EBCs is mediated by a set of tailored plasma and vacuole membrane-based sodium-selective channel and chloride-permeable transporter.
•HKT1-type channels mediate a one-way sodium load into quinoa bladder cells•ClC transporters operate in the Cl− sequestration into vacuoles of bladder cells•The bladder cytoplasm is osmotically balanced by potassium and proline import•On the transcript level, bladders are “constitutively active” for salt sequestration
Böhm et al. report that the inward-rectifier CqHKT1.2 is a key player for the Na+ load into bladder cells under salinity stress. Together with transporters for compatible solutes, these transport systems mediate sequestration of salt into bladders, arming quinoa with an efficient mechanism to protect the metabolically active photosynthetic tissues.
Date palms are remarkably tolerant to environmental stresses, but the mechanisms involved remain poorly characterized. Leaf metabolome profiling was therefore performed on mature (ML) and young (YL) ...leaves of 2-year-old date palm seedlings that had been grown in climate chambers that simulate summer and winter conditions in eastern Saudi Arabia. Cultivation under high temperature (summer climate) resulted in higher YL H2O2 leaf levels despite increases in dehydroascorbate reductase (DHAR) activities. The levels of raffinose and galactinol, tricarboxylic acid cycle intermediates, and total amino acids were higher under these conditions, particularly in YL. The accumulation of unsaturated fatty acids, 9,12-octadecadienoic acid and 9,12,15-octadecatrienoic acid, was lower in ML. In contrast, the amounts of saturated tetradecanoic acid and heptadecanoic acid were increased in YL under summer climate conditions. The accumulation of phenolic compounds was favored under summer conditions, while flavonoids accumulated under lower temperature (winter climate) conditions. YL displayed stronger hydration, lower H2O2 levels, and more negative δ 13C values, indicating effective reactive oxygen species scavenging. These findings, which demonstrate the substantial metabolic adjustments that facilitate tolerance to the high temperatures in YL and ML, suggest that YL may be more responsive to climate change.
Water limitation of plants causes stomatal closure to prevent water loss by transpiration. For this purpose, progressing soil water deficit is communicated from roots to shoots. Abscisic acid (ABA) ...is the key signal in stress-induced stomatal closure, but ABA as an early xylem-delivered signal is still a matter of debate. In this study, poplar plants (Populus × canescens) were exposed to water stress to investigate xylem sap sulfate and ABA, stomatal conductance, and sulfate transporter (SULTR) expression. In addition, stomatal behavior and expression of ABA receptors, drought-responsive genes, transcription factors, and NCED3 were studied after feeding sulfate and ABA to detached poplar leaves and epidermal peels of Arabidopsis (Arabidopsis thaliana). The results show that increased xylem sap sulfate is achieved upon drought by reduced xylem unloading by PtaSULTR3;3a and PtaSULTR1;1, and by enhanced loading from parenchyma cells into the xylem via PtaALMT3b. Sulfate application caused stomatal closure in excised leaves and peeled epidermis. In the loss of sulfate-channel function mutant, Atalmt12, sulfate-triggered stomatal closure was impaired. The QUAC1/ALMT12 anion channel heterologous expressed in oocytes was gated open by extracellular sulfate. Sulfate up-regulated the expression of NCED3, a key step of ABA synthesis, in guard cells. In conclusion, xylem-derived sulfate seems to be a chemical signal of drought that induces stomatal closure via QUAC1/ALMT12 and/or guard cell ABA synthesis.
S-type anion channels are direct targets of abscisic acid (ABA) signaling and contribute to chloride and nitrate release from guard cells, which in turn initiates stomatal closure. SLAC1 was the ...first component of the guard cell S-type anion channel identified. However, we found that guard cells of Arabidopsis SLAC1 mutants exhibited nitrate conductance. SLAH3 (SLAC1 homolog 3) was also present in guard cells, and coexpression of SLAH3 with the calcium ion (Ca2+)-dependent kinase CPK21 in Xenopus oocytes mediated nitrate-induced anion currents. Nitrate, calcium, and phosphorylation regulated SLAH3 activity. CPK21-dependent SLAH3 phosphorylation and activation were blocked by ABI1, a PP2C-type protein phosphatase that is inhibited by ABA and inhibits the ABA signaling pathway in guard cells. We reconstituted the ABA-stimulated phosphorylation of the SLAH3 amino-terminal domain by CPK21 in vitro by including the ABA receptor-phosphatase complex RCAR1-ABI1 in the reactions. We propose that ABA perception by the complex consisting of ABA receptors of the RCAR/PYR/PYL family and ABI1 releases CPK21 from inhibition by ABI1, and then CPK21 is further activated by an increase in the cytosolic Ca2+ concentration, leading to its phosphorylation of SLAH3. Thus, the identification of SLAH3 as the nitrate-, calcium-, and ABA-sensitive guard cell anion channel provides insights into the relationship among stomatal response to drought, signaling by nitrate, and nitrate metabolism.
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