O dever de obediência a ordens ilegais na Guarda Nacional Republicana

The Republican National Guard (GNR) is a military structure and hierarchical force where discipline and obedience is a serious matter, but at the same time, the scope of its activity relates to the protection of the rights, freedoms and guarantees of citizens and the primacy of public interest. While security force, GNR ensures democratic law, guarantee the internal security and the rights of citizens. The controversial issue that lies at the heart of this work its related with the balance between the hierarchy and the written law. The hierarchy, also established by law, with given powers, exist to apply the law. However, the rule of law has exceptions. Which institute to prioritize, hierarchy or the law. And within the law, its rules or the exceptions. Who decides? The GNR's officers have to obey the laws and regulations and comply with the accuracy and timeliness determinations, orders and instructions issued by a superior, given in terms of service, as long as does not involve the practice of crime. The GNR´s officer with command tasks exercises power of authority inherent in these functions, and the corresponding disciplinary authority, being responsible for acts by himself or by his order are practiced. Identify situations of exception to law enforcement, the situations in which one must obey illegal orders, is difficult and thankless, it requires conferred authority and raises the weight of responsibility for decisions and orders issued.

Occupational stress and coping among portuguese military police officers

This study describes the professional experience of military police officers from the Portuguese Republican National Guard (N = 95). We focused on the main sources and consequences of stress and the coping strategies used to deal with stress. The evaluation protocol included one closed-ended question and four open-ended questions. Data analysis of meaningful text segments was conceptually based and data categorization followed deductive content analysis. Results allowed the identification of 483 meaning units. Factors intrinsic to the job and the relationships at work were the main stressors referred by participants. The consequences of stressors were evident at an individual level, affecting family, psychological, and physical/health domains. The coping strategies used to deal with the main source of stress in the professional career were focused on problem solving (e.g., active confrontation) and emotional regulation (e.g., situation acceptance). Practical implications and future avenues of research with these professionals are discussed.

Tulevaisuuden lähtökohdista kansanvallan kolmiliittoon. Kansallinen Edistyspuolue ja kansallisen eheytymisen politiikka 1919–1939.

Kansallista Edistyspuoluetta ja sen toimijoita maailmansotien välisen Suomen sisäpolitiikassa tarkasteleva väitöstutkimus paneutuu puolueen kansallista eheytymistä ajaneen poliittisen linjan taustoihin, muodostumiseen ja toteutumiseen maailmansotien välisenä aikana vuosina 1919-1939. Vahvasti aineistopohjainen ja lähdekriittinen poliittisen historian tutkimus keskittyy parlamentaarisiin toimijoihin, poliittiseen kenttään ja näiden tuottamiin aineistoihin, kuten edistyspuolueen ja sen toimijoiden arkistoihin, lehdistöön ja valtiopäiväpöytäkirjoihin. Tutkimus selvittää, millainen oli edistyspuolueen kansallisen eheytymisen linja, mihin sillä pyrittiin, miten sitä toteutettiin ja miten se toteutui. Kansainvälisen vertailun kautta tutkimuksessa luodaan myös kuva suomalaisesta liberalismista ja liberalistista. Joulukuussa 1918 perustettu Kansallinen Edistyspuolue oli liberaali puolue, jonka politiikassa korostui erityisesti liberalismin sosiaalinen tulkinta. Puolueen sisäpoliittiseksi linjaksi vastaitsenäistyneessä ja sisällissodan runtelemassa valtiossa muodostui kansallisen eheytymisen edistäminen. Ajatuksen taustalla olivat K. J. Ståhlbergin tulevaisuuden lähtökohtia hahmotelleet artikkelit, jotka julkaistiin Helsingin Sanomissa huhtikuussa 1918 sisällissodan vielä riehuessa. Ståhlbergin mukaan kansalliseen eheytymiseen ei tullut pyrkiä sodan vuoksi vaan siitä huolimatta. Nuorsuomalaiselta puolueelta perityt liberaalit periaatteet täydentyivätkin edistyspuoluelaisessa ajattelussa sisällissodan ja tasavallan puolesta käydyn valtiomuototaistelun avainkokemuksilla. Itsenäisen Suomen ensimmäisiä vuosia hallinneissa keskustahallituksissa kansallista eheytymistä edistettiin sosiaalipoliittisin uudistuksin mm. oppivelvollisuus- ja asutuslakien muodossa. Myös sisällissodan vankien armahdukset olivat osa tätä ohjelmaa. Tutkimus osoittaa, että edistyspuolueen kansallisen eheytymisen politiikan keskeisenä tavoitteena oli poliittisen sovittelun kautta integroida vasemmisto osaksi parlamentaaris-demokraattista järjestelmää. Eheytyspolitiikan todellinen käyttöarvo ja edistyspuolueen poliittiset toimintamahdollisuudet alkoivat kuitenkin heiketä vuoden 1922 eduskuntavaalien jälkeen.Tutkimuksesta käy ilmi, että toteutettu eheytyspolitiikka ja sen osittainen epäonnistuminen näkyivät sekä kommunistien jatkuvana kannatuksena että sisäpoliittisen ilmapiirin oikeistolaistumisena. Tämä kehitys nosti myös edistyspuolueessa esille voimat, jotka suosivat porvariyhteistyötä ohi keskustavasemmistolaisen eheytyspoliittisen linjan. Alkuvuosien jälkeen valtiomuototaistelun koossapitävä voima heikkeni edistyspuolueen sisällä ja 1920-luvun puolivälissä käydyt linjakiistat osoittivat, että osalle puolueen jäsenistä vuoden 1918 puoluevalinnassa keskeisemmässä roolissa oli ollut tasavaltalaisuus kuin vasemmiston integrointi ja kansallinen eheytyminen. Edistyspuolueen johto ei kuitenkaan ollut valmis luopumaan eheytyspoliittisesta linjasta ja sen ympärille luodusta puolueidentiteetistä, joten porvariyhteistyötä kannattanut oikeisto-oppositio päätyi suurelta osin eroamaan puolueesta vuonna 1927. Tutkimus osoittaa, että parlamentarismin rapautuminen ja pienelle yleispuolueelle elintärkeiden yhteistyömahdollisuuksien heikkeneminen luokkapuolueiden puristuksessa johtivat edistyspuolueen kannatuksen alamäkeen sotien välisenä aikana. Se kutistui 26 kansanedustajan keskisuuresta puolueesta vain kuuden edustajan pienpuolueeksi. Puolueidentiteetin vahvuus ja keskeisten toimijoiden puolueen kokoa suurempi poliittinen painoarvo pitivät sen lakkauttamispohdinnoista huolimatta kuitenkin koossa ja kiinni politiikan ytimessä. Oikeistoradikalismin vuodet 1920–1930-lukujen taitteessa olivat edistyspuolueellesekä uhka että mahdollisuus. Tutkimuksessa käy ilmi, että vaikka kommunisminvastaisen kansanliikkeen vaatimukset olivat edistyspuoluelaisten mielestä oikeutettuja, oli kansanliikkeen niiden ajamiseksi omaksumia laittomia ja ulkoparlamentaarisia keinoja vaikea hyväksyä. Eheytyspolitiikan kannalta katsottuna melkotoivottamalta näyttänyt tilanne kääntyi kuitenkin lopulta voitoksi: äärivasemmisto eliminoitiin, äärioikeisto ajautui paitsioon ja tie maltillisen vasemmiston ja keskustan yhteistyölle aukesi jälleen. Tämä johti lopulta vuonna 1937 punamultahallitukseen ja kansanvallan kolmiliittoon Kansallisen Edistyspuolueen, SDP:n ja Maalaisliiton kesken. Kokemus siitä, että itsenäisyys oli alati uhattuna, toi suomalaiseen liberalismiin varsin nationalistisia piirteitä, joita eurooppalaisten veljespuolueiden ohjelmista ei löydy. Liberalismiin usein liitetty mielleyhtymä sen kosmopoliittisesta, kansallisvaltioita ylittävästä luonteesta jäi Suomessa sotien välisenä aikana nationalismin ja itäisen naapurin luoman uhan varjoon. Suomen sisäpoliittinen tilanne ja geopoliittinen asema loivat vaatimuksen vahvasta kansallisesta yhtenäisyydestä. Suomalainen liberalismi määrittyikin eurooppalaisia vastineitaan voimakkaammin nuorta valtiota hallinneen kansallisuusajattelun, itsesäilytysvaiston ja kansallisen eheyden vaatimusten kautta. Tutkimuksessa todetaan, että edistyspuolueen eheytyspoliittisen linjan muotoutumista ja toteutumista vuosien 1919‒1939 aikana voi pitää idealismin voittona realismista. Lukuun ottamatta reformipolitiikan vuosia edistyspuolueen pitäytyminen valitulla linjalla näyttäytyi poliittisten toimintamahdollisuuksien kannalta katsottuna ajoittain jopa epärealistiselta. Koko sotien välistä aikaa tarkastellessa voikin todeta, että se, minkä edistyspuolue poliittisten päämäärien saavuttamisen valossa voitti, sen se menetti kannatusluvuissa.

National Intelligencer Vol. XIII, No. 1984- June 8, 1813

The Intelligencer was an American newspaper that was established, in 1800, in Washington by Samuel Harrison Smith, a young Jeffersonian- Republican from Philadelphia. The paper was a supporter of the Jefferson and Madison administrations until 1810 when it was sold to Joseph Gales Jr. from North Carolina. In 1812 William Seaton joined Gales as a publishing partner. This paper made significant contributions to the nation and wielded considerable influence in political circles during its publication. It has been praised for its "high standard of journalistic excellence and high intellectual level of its contents". (William E. Ames , National Intelligencer: Washington's Leading Political Newspaper) The Intelligencer was, until 1810, named the National Intelligencer, and Washington Advertiser. It was a tri-weekly paper and had a peak circulation of 6, 000. Publication was suspended in 1869.

National Intelligencer Vol. XIII, No. __91- June 24, 1813

The Intelligencer was an American newspaper that was established, in 1800, in Washington by Samuel Harrison Smith, a young Jeffersonian- Republican from Philadelphia. The paper was a supporter of the Jefferson and Madison administrations until 1810 when it was sold to Joseph Gales Jr. from North Carolina. In 1812 William Seaton joined Gales as a publishing partner. This paper made significant contributions to the nation and wielded considerable influence in political circles during its publication. It has been praised for its "high standard of journalistic excellence and high intellectual level of its contents". (William E. Ames , National Intelligencer: Washington's Leading Political Newspaper) The Intelligencer was, until 1810, named the National Intelligencer, and Washington Advertiser. It was a tri-weekly paper and had a peak circulation of 6, 000. Publication was suspended in 1869.

National Intelligencer Vol. XIII, No. 1993- June 29, 1813

The Intelligencer was an American newspaper that was established, in 1800, in Washington by Samuel Harrison Smith, a young Jeffersonian- Republican from Philadelphia. The paper was a supporter of the Jefferson and Madison administrations until 1810 when it was sold to Joseph Gales Jr. from North Carolina. In 1812 William Seaton joined Gales as a publishing partner. This paper made significant contributions to the nation and wielded considerable influence in political circles during its publication. It has been praised for its "high standard of journalistic excellence and high intellectual level of its contents". (William E. Ames , National Intelligencer: Washington's Leading Political Newspaper) The Intelligencer was, until 1810, named the National Intelligencer, and Washington Advertiser. It was a tri-weekly paper and had a peak circulation of 6, 000. Publication was suspended in 1869.

National Intelligencer Vol. XVI, No. 2193- October 15, 1814

The Intelligencer was an American newspaper that was established, in 1800, in Washington by Samuel Harrison Smith, a young Jeffersonian- Republican from Philadelphia. War of 1812 related content includes: Page 1: Major General Winfield Scott's arrival in Washington escorted by Colonel Laval's cavalry; report from Sackett's Harbour on the American and British navies; a debate on a bill to temporarily remove the seat of government from the City of Washington due to the war; the Military Committee wishing to have the President commission gold medals for distinguished service for Major Generals Brown and Scott and silver medals to Brigadier Generals Ripley, Miller and Porter for their efforts at Chippewa, Erie and Niagara as well as gold medals to Brigadier General Gaines for efforts at Erie and Brigadier General Macomb for efforts at Plattsburg; resolutions of the House on the victory of Commodore Thomas Macdonough at the Battle on Lake Champlain; Page 2: more detail on the proposed removal of the seat of government from Washington; Page 3: a letter from Major General Andrew Jackson to the Secretary of War on repelling the British at Fort Bowyer on the Point of Mobile and naval battle reports on the vessels Hermes, Sophie, and Carron; a letter from Major William Lawrence to Andrew Jackson on the battle at Fort Bowyer; military promotions of Alexander Macomb, Roger Jones, J. Hindman; more on the removal of the seat of government; citizens of Washington offering to volunteer in defense of the city; banks willing to loan the government funds to re-build destroyed government buildings; assignments of Major General Scott, General Winder and Major General Gaines; report of 300 British prisoners from Fort Erie passed through Washington; Montreal newspaper report condemning Provost for his actions at the Battle of Lake Champlain; trouble with stage coaches traveling between New Haven and Bridgeport due to cannon fire; report of a British naval squadron appearing off New Port and by Long Island and New Bedford; report of enemy naval movements from Norfolk; announcement of a book entitled "A Narrative of the Battle of Bladensburg" by and officer of General Smith; Page 4: report on the amassing navy at Kingston under Drummond and the defenses at Sackett's Harbor; report of American and British naval news from Nova Scotia and the east coast; actions of the American sloop of war, The Peacock, in international waters; an enlistment announcement by Captain Perrin Willis of the 2nd Regiment Infantry; listing of American officers and privates released from parole on October 13; Other notices report on stray horses, properties for sale, runaway slaves, imprisonments, missing livestock, medical lectures at the University of Maryland, stage lines, auctions, etc. The paper was a supporter of the Jefferson and Madison administrations until 1810 when it was sold to Joseph Gales Jr. from North Carolina. In 1812 William Seaton joined Gales as a publishing partner. This paper made significant contributions to the nation and wielded considerable influence in political circles during its publication. It has been praised for its "high standard of journalistic excellence and high intellectual level of its contents". (William E. Ames , National Intelligencer: Washington's Leading Political Newspaper) The Intelligencer was, until 1810, named the National Intelligencer, and Washington Advertiser. It was a tri-weekly paper and had a peak circulation of 6, 000. Publication was suspended in 1869.

National Intelligencer, 10 November 1812 (vol. 13, no. 1895) - Newspaper

The Intelligencer was an American newspaper that was established in Washington by Samuel Harrison Smith, a young Jeffersonian-Republican from Philadelphia. The paper was a supporter of the Jefferson and Madison administrations until 1810 when it was sold to Joseph Gales Jr. from North Carolina. In 1812 William Seaton joined Gales as a publishing partner. The paper made significant contributions to the nation and wielded considerable influence in political circles during its publication

Archives information publishing new design in post-custodial regime: The National Archives Experience Digital Vaults

The uses of Information and Communication Technologies (ICT) and Web environments for creation, treatment and availability of information have supported the emergence of new social-cultural patterns represented by convergences in textual, image and audio languages. This paper describes and analyzes the National Archives Experience Digital Vaults as a digital publishing web environment and as a cultural heritage. It is a complex system - synthesizer of information design options at information setting, provides new aesthetic aspects, but specially enlarges the cognition of the subjects who interact with the environment. It also enlarges the institutional spaces that guard the collective memory beyond its role of keeping the physical patrimony collected there. Digital Vaults lies as a mix of guide and interactive catalogue to be dealt in a ludic way. The publishing design of the information held on the Archives is meant to facilitate access to knowledge. The documents are organized in a dynamic and not chronological way. They are not divided in fonds or distinct categories, but in controlled interaction of documents previously indexed and linked by the software. The software creates information design and view of documental content that can be considered a new paradigm in Information Science and are part of post-custodial regime, independent from physical spaces and institutions. Information professionals must be prepared to understand and work with the paradigmatic changes described and represented by the new hybrid digital environments; hence the importance of this paper. Cyberspace interactivity between user and the content provided by the environment design provide cooperation, collaboration and sharing knowledge actions, all features of networks, transforming culture globally. © 2011 - IOS Press and the authors. All rights reserved.

Archives information publishing new design in post-custodial regime: The National Archives Experience Digital Vaults

The uses of Information and Communication Technologies (ICT) and Web environments for creation, treatment and availability of information have supported the emergence of new social-cultural patterns represented by convergences in textual, image and audio languages. This paper describes and analyzes the National Archives Experience Digital Vaults as a digital publishing web environment and as a cultural heritage. It is a complex system - synthesizer of information design options at information setting, provides new aesthetic aspects, but specially enlarges the cognition of the subjects who interact with the environment. It also enlarges the institutional spaces that guard the collective memory beyond its role of keeping the physical patrimony collected there. Digital Vaults lies as a mix of guide and interactive catalogue to be dealt in a ludic way. The publishing design of the information held on the Archives is meant to facilitate access to knowledge. The documents are organized in a dynamic and not chronological way. They are not divided in fonds or distinct categories, but in controlled interaction of documents previously indexed and linked by the software. The software creates information design and view of documental content that can be considered a new paradigm in Information Science and are part of post-custodial regime, independent from physical spaces and institutions. Information professionals must be prepared to understand and work with the paradigmatic changes described and represented by the new hybrid digital environments; hence the importance of this paper. Cyberspace interactivity between user and the content provided by the environment design provide cooperation, collaboration and sharing knowledge actions, all features of networks, transforming culture globally.

Archives information publishing new design in post-custodial regime: the national archives experience digital vaults

The uses of Information and Communication Technologies (ICT) and Web environments for creation, treatment and availability of information have supported the emergence of new social-cultural patterns represented by convergences in textual, image and audio languages. This paper describes and analyzes the National Archives Experience Digital Vaults as a digital publishing web environment and as a cultural heritage. It is a complex system - synthesizer of information design options at information setting, provides new aesthetic aspects, but specially enlarges the cognition of the subjects who interact with the environment. It also enlarges the institutional spaces that guard the collective memory beyond its role of keeping the physical patrimony collected there. Digital Vaults lies as a mix of guide and interactive catalogue to be dealt in a ludic way. The publishing design of the information held on the Archives is meant to facilitate access to knowledge. The documents are organized in a dynamic and not chronological way. They are not divided in fonds or distinct categories, but in controlled interaction of documents previously indexed and linked by the software. The software creates information design and view of documental content that can be considered a new paradigm in Information Science and are part of post-custodial regime, independent from physical spaces and institutions. Information professionals must be prepared to understand and work with the paradigmatic changes described and represented by the new hybrid digital environments; hence the importance of this paper. Cyberspace interactivity between user and the content provided by the environment design provide cooperation, collaboration and sharing knowledge actions, all features of networks, transforming culture globally.

Executive Reorganization: Building a State Government That Worked for People -- Tom Harrison, Diana Dowling & Sheena Wilson “In the Crucible of Change”

One of the primary accomplishments of Governor Forrest Anderson in 1969-71 was the reorganization of the Executive Branch of Montana government, something that had been attempted six different times between 1919 and 1962 as state government had grown from twenty agencies to almost 200 uncontrolled boards, bureaus and commissions. The chaotic structure of the executive branch disempowered governors of both parties and empowered the private corporations and organizations that were the power structure of Montana. With remarkable political acumen, Governor Anderson figured out how to get that near impossible job done. Central to his efforts was the creation of an Executive Reorganization Commission, including eight legislators and the Governor, the adoption of a Constitutional Amendment that limited the executive branch to no more than twenty departments under the Governor, and the timely completion of a massive research effort to delineate the actual structure of the twenty departments. That story is told in this episode by three major players in the effort, all involved directly with the Executive Reorganization Commission: Tom Harrison, Diana Dowling and Sheena Wilson. Their recollections reflect an insider’s perspective of this significant accomplishment that helped change Montana “In the Crucible of Change.” Tom Harrison is a former Republican State Representative and State Senator from Helena, who was a member of the Executive Reorganization Commission. As Majority Leader in the Montana House of Representatives in 1971, he was the primary sponsor of the House’s executive reorganization bill and helped shepherd the Senate’s version to passage. Harrison was the Republican candidate for Attorney General in 1976 after which he practiced private law for 3 more decades. He served in the Montana Army National Guard for almost 34 years, rising to the rank of Colonel in the position of Judge Advocate General. He was a founding Director of Federal Defenders of Montana (legal representation for indigents accused within the Federal Judicial System); appointed Chairman of the original Montana State Fund (workers' compensation insurance) by Gov. Stephens; served as President of the Montana Trial Lawyers Association, Helena Kiwanis Club and St. Peter's Community Hospital Foundation, as well as Chairman and Director of AAA MountainWest; and was a founder, first Chairman and Director of the Valley Bank of Helena for over 25 years. Diana Dowling was an attorney for the Executive Reorganization Commission and helped draft the legislation that was passed. She also worked for Governor Forrest Anderson and for the 1972 Constitutional Convention where she prepared and directed publication of official explanation of the new Constitution that was mailed to all Montana voters. Diana was Executive Director of the Montana Bar Association and for 20 years held various legal positions with the Montana Legislative Council. For 12 years she was a commissioner on the National Conference of Commissioners on Uniform State Laws and for 7 years was a member of Montana State Board of Bar Examiners. Diana was the first director of the Montana Lottery, an adjunct professor at both Carroll College and the UM Law School, and an administrative officer for Falcon Press Publishing Co. Diana is currently - and intends to continue being - a perpetual college student. Sheena Wilson came fresh out of the University of Montana to become a Research Assistant for the Executive Reorganization Commission. Later she worked for seven years as a field representative in Idaho and Montana for the Mountain Plains Family Education Program, for thirteen years with Congressman Pat Williams as Executive Assistant in Washington and Field Assistant here in Montana, owned and managed a Helena restaurant for seven years, worked as Executive Assistant for State Auditor John Morrison and was Deputy Chief of Staff for Governor Brian Schweitzer his full 8 years in the Governorship. Though currently “retired”, Sheena serves on the Montana Board of Investments, the Public Employees Retirement Board and the Capitol Complex Advisory Council and is a partner in a dry-land wheat farm in Teton County that was homesteaded by her great uncle.

Membrane voltage initiates Ca2+ waves and potentiates Ca2+ increases with abscisic acid in stomatal guard cells

In higher plants changes and oscillations in cytosolic free Ca2+ concentration ([Ca2+]i) are central to hormonal physiology, including that of abscisic acid (ABA), which signals conditions of water stress and alters ion channel activities in guard cells of higher-plant leaves. Such changes in [Ca2+]i are thought to encode for cellular responses to different stimuli, but their origins and functions are poorly understood. Because transients and oscillations in membrane voltage also occur in guard cells and are elicited by hormones, including ABA, we suspected a coupling of [Ca2+]i to voltage and its interaction with ABA. We recorded [Ca2+]i by Fura2 fluorescence ratio imaging and photometry while bringing membrane voltage under experimental control with a two-electrode voltage clamp in intact Vicia guard cells. Free-running oscillations between voltages near −50 mV and −200 mV were associated with oscillations in [Ca2+]i, and, under voltage clamp, equivalent membrane hyperpolarizations caused [Ca2+]i to increase, often in excess of 1 μM, from resting values near 100 nM. Image analysis showed that the voltage stimulus evoked a wave of high [Ca2+]i that spread centripetally from the peripheral cytoplasm within 5–10 s and relaxed over 40–60 s thereafter. The [Ca2+]i increases showed a voltage threshold near −120 mV and were sensitive to external Ca2+ concentration. Substituting Mn2+ for Ca2+ to quench Fura2 fluorescence showed that membrane hyperpolarization triggered a divalent influx. ABA affected the voltage threshold for the [Ca2+]i rise, its amplitude, and its duration. In turn, membrane voltage determined the ability of ABA to raise [Ca2+]i. These results demonstrate a capacity for voltage to evoke [Ca2+]i increases, they point to a dual interaction with ABA in triggering and propagating [Ca2+]i increases, and they implicate a role for voltage in “conditioning” [Ca2+]i signals that regulate ion channels for stomatal function.

Ozone inhibits guard cell K+ channels implicated in stomatal opening

Ozone (O3) deleteriously affects organisms ranging from humans to crop plants, yet little is understood regarding the underlying mechanisms. In plants, O3 decreases CO2 assimilation, but whether this could result from direct O3 action on guard cells remained unknown. Potassium flux causes osmotically driven changes in guard cell volume that regulate apertures of associated microscopic pores through which CO2 is supplied to the photosynthetic mesophyll tissue. We show in Vicia faba that O3 inhibits (i) guard cell K+ channels that mediate K+ uptake that drives stomatal opening; (ii) stomatal opening in isolated epidermes; and (iii) stomatal opening in leaves, such that CO2 assimilation is reduced without direct effects of O3 on photosynthetic capacity. Direct O3 effects on guard cells may have ecological and agronomic implications for plant productivity and for response to other environmental stressors including drought.

Inositol hexakisphosphate is a physiological signal regulating the K+-inward rectifying conductance in guard cells

(RS)-2-cis, 4-trans-abscisic acid (ABA), a naturally occurring plant stress hormone, elicited rapid agonist-specific changes in myo-inositol hexakisphosphate (InsP6) measured in intact guard cells of Solanum tuberosum (n = 5); these changes were not reproduced by (RS)-2-trans, 4-trans-abscisic acid, an inactive stereoisomer of ABA (n = 4). The electrophysiological effects of InsP6 were assessed on both S. tuberosum (n = 14) and Vicia faba (n = 6) guard cell protoplasts. In both species, submicromolar concentrations of InsP6, delivered through the patch electrode, mimicked the inhibitory effects of ABA and internal calcium (Cai2+) on the inward rectifying K+ current, IK,in, in a dose-dependent manner. Steady state block of IK,in by InsP6 was reached much more quickly in Vicia (3 min at ≈1 μM) than Solanum (20–30 min). The effects of InsP6 on IK,in were specific to the myo-inositol isomer and were not elicited by other conformers of InsP6 (e.g., scyllo- or neo-). Chelation of Ca2+ by inclusion of 1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid or EGTA in the patch pipette together with InsP6 prevented the inhibition of IK,in, suggesting that the effect is Ca2+ dependent. InsP6 was ≈100-fold more potent than Ins(1,4,5)P3 in modulating IK,in. Thus ABA increases InsP6 in guard cells, and InsP6 is a potent Ca2+-dependent inhibitor of IK,in. Taken together, these results suggest that InsP6 may play a major role in the physiological response of guard cells to ABA.