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Less than 10% of the estimated average requirement (EAR) for iron and zinc is provided by consumption of storage roots of the staple crop cassava (Manihot esculenta Crantz) in West African human populations. We used genetic engineering to improve mineral micronutrient concentrations in cassava. Overexpression of the Arabidopsis thaliana vacuolar iron transporter VIT1 in cassava accumulated three- to seven-times-higher levels of iron in transgenic storage roots than nontransgenic controls in confined field trials in Puerto Rico. Plants engineered to coexpress a mutated A. thaliana iron transporter (IRT1) and A. thaliana ferritin (FER1) accumulated iron levels 7–18 times higher and zinc levels 3–10 times higher than those in nontransgenic controls in the field. Growth parameters and storage-root yields were unaffected by transgenic fortification in our field data. Measures of retention and bioaccessibility of iron and zinc in processed transgenic cassava indicated that IRT1 + FER1 plants could provide 40–50% of the EAR for iron and 60–70% of the EAR for zinc in 1- to 6-year-old children and nonlactating, nonpregnant West African women.Cassava, a staple crop consumed by 800 million people, is enriched in iron and zinc through genetic biofortification.

Transitory starch is stored during the day inside chloroplasts and broken down at night for export. Maltose is the primary form of carbon export from chloroplasts at night. We investigated the influence of daylength and circadian rhythms on starch degradation and maltose metabolism. Starch breakdown was faster in plants of Arabidopsis (Arabidopsis thaliana) ecotype Wassilewskija growing in long days. Transcript levels of genes encoding enzymes involved in starch degradation and maltose metabolism showed a strong diurnal rhythm. Under altered photoperiods, the transcript levels and the rate of starch degradation changed within one day/night cycle. However, the amount of proteins involved in starch degradation was maintained relatively constant throughout the day/night cycle. To investigate whether the diurnal cycling of the transcript levels is only a response to light or is also regulated by a circadian clock, we measured the amount of messenger RNAs in Arabidopsis leaves under continuous light and continuous darkness. The expression of genes encoding starch degradation-related enzymes was under very strong circadian control in continuous light. Under continuous light, the amount of maltose also showed a strong endogenous rhythm close to 24 h, indicating that maltose metabolism is under circadian control. Light is necessary for the cycling of transcript levels and maltose levels. Under continuous darkness, these genes were barely expressed, and no cycling of maltose levels was observed.

Summary Storage roots of cassava (Manihot esculenta Crantz), a major subsistence crop of sub‐Saharan Africa, are calorie rich but deficient in essential micronutrients, including provitamin A β‐carotene. In this study, β‐carotene concentrations in cassava storage roots were enhanced by co‐expression of transgenes for deoxy‐d‐xylulose‐5‐phosphate synthase (DXS) and bacterial phytoene synthase (crtB), mediated by the patatin‐type 1 promoter. Storage roots harvested from field‐grown plants accumulated carotenoids to ≤50 μg/g DW, 15‐ to 20‐fold increases relative to roots from nontransgenic plants. Approximately 85%–90% of these carotenoids accumulated as all‐trans‐β‐carotene, the most nutritionally efficacious carotenoid. β‐Carotene‐accumulating storage roots displayed delayed onset of postharvest physiological deterioration, a major constraint limiting utilization of cassava products. Large metabolite changes were detected in β‐carotene‐enhanced storage roots. Most significantly, an inverse correlation was observed between β‐carotene and dry matter content, with reductions of 50%–60% of dry matter content in the highest carotenoid‐accumulating storage roots of different cultivars. Further analysis confirmed a concomitant reduction in starch content and increased levels of total fatty acids, triacylglycerols, soluble sugars and abscisic acid. Potato engineered to co‐express DXS and crtB displayed a similar correlation between β‐carotene accumulation, reduced dry matter and starch content and elevated oil and soluble sugars in tubers. Transcriptome analyses revealed a reduced expression of genes involved in starch biosynthesis including ADP‐glucose pyrophosphorylase genes in transgenic, carotene‐accumulating cassava roots relative to nontransgenic roots. These findings highlight unintended metabolic consequences of provitamin A biofortification of starch‐rich organs and point to strategies for redirecting metabolic flux to restore starch production.

Cassava mosaic disease (CMD) suppresses cassava yields across the tropics. The dominant CMD2 locus confers resistance to cassava mosaic geminiviruses. It has been reported that CMD2-type landraces lose resistance after regeneration through de novo morphogenesis. As full genome bisulfite sequencing failed to uncover an epigenetic mechanism for this loss of resistance, whole genome sequencing and genetic variant analysis was performed and the CMD2 locus was fine-mapped to a 190 kilobase interval. Collectively, these data indicate that CMD2-type resistance is caused by a nonsynonymous, single nucleotide polymorphism in DNA polymerase δ subunit 1 ( MePOLD1 ) located within this region. Virus-induced gene silencing of MePOLD1 in a CMD-susceptible cassava variety produced a recovery phenotype typical of CMD2-type resistance. Analysis of other CMD2-type cassava varieties identified additional candidate resistance alleles within MePOLD1 . Genetic variation of MePOLD1 , therefore, could represent an important genetic resource for resistance breeding and/or genome editing, and elucidating mechanisms of resistance to geminiviruses. Cassava mosaic disease is caused by geminiviruses and suppresses cassava yields throughout the tropics. Here, the authors show that mutations in MePOLD1 , encoding DNA polymerase δ subunit 1, co-segregate with CMD2 , the major source of genetic resistance for this disease.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Key messageAmong the five cassava isoforms (MeAPL1–MeAPL5), MeAPL3 is responsible for determining storage root starch content. Degree of storage root postharvest physiological deterioration (PPD) is directly correlated with starch content.AGPase is heterotetramer composed of two small and two large subunits each coded by small gene families in higher plants. Studies in cassava (Manihot esculenta) identified and characterized five isoforms of Manihot esculenta ADP-glucose pyrophosphorylase large subunit (MeAPL1–MeAPL5) and employed virus induced gene silencing (VIGS) to show that MeAPL3 is the key isoform responsible for starch and dry matter accumulation in cassava storage roots. Silencing of MeAPL3 in cassava through stable transgenic lines resulted in plants displaying significant reduction in storage root starch and dry matter content (DMC) and induced a distinct phenotype associated with increased petiole/stem angle, resulting in a droopy leaf phenotype. Plants with reduced starch and DMC also displayed significantly reduced or no postharvest physiological deterioration (PPD) compared to controls and lines with high DMC and starch content. This provides strong evidence for direct relationships between starch/dry matter content and its role in PPD and canopy architecture traits in cassava.

Transitory starch is stored during the day inside chloroplasts and broken down at night for export. Maltose is the primary form of carbon export from chloroplasts at night. We investigated the influence of daylength and circadian rhythms on starch degradation and maltose metabolism. Starch breakdown was faster in plants of Arabidopsis (Arabidopsis thaliana) ecotype Wassilewskija growing in long days. Transcript levels of genes encoding enzymes involved in starch degradation and maltose metabolism showed a strong diurnal rhythm. Under altered photoperiods, the transcript levels and the rate of starch degradation changed within one day/night cycle. However, the amount of proteins involved in starch degradation was maintained relatively constant throughout the day/night cycle. To investigate whether the diurnal cycling of the transcript levels is only a response to light or is also regulated by a circadian clock, we measured the amount of messenger RNAs in Arabidopsis leaves under continuous light and continuous darkness. The expression of genes encoding starch degradation-related enzymes was under very strong circadian control in continuous light. Under continuous light, the amount of maltose also showed a strong endogenous rhythm close to 24 h, indicating that maltose metabolism is under circadian control. Light is necessary for the cycling of transcript levels and maltose levels. Under continuous darkness, these genes were barely expressed, and no cycling of maltose levels was observed.

PlantCV is an open-source Python project aimed at developing tools to address a range of image-based, plant phenotyping questions. PlantCV has been used for more than 10 years to automate trait collection from image data and the newest release, PlantCV version 4, continues to lower the barrier to entry for users without substantial coding experience through extensive example use-case tutorials and simplified installation. In addition to usability, we document added functionality since the release of PlantCV v2, including support for more image types such as fluorescence, thermal, and hyperspectral data. Finally, we describe the development of a new subpackage focused on morphological trait measurements like leaf angle, and demonstrate its utility as compared to more manual methods of data collection. PlantCV is an open-source, open-development, Python-based software package that has a new release for improved functionality and usability to make image analysis flexible and easier for researchers without a coding background. PlantCV is now capable of handling new data types that are relevant to researchers, such as thermal and hyperspectral, and has built in functionality for extracting information from these image types. The software project aims to lower the barrier to entry into image analysis for researchers by providing numerous, versioned, interactive tutorials that cover most common use cases, particularly in plant science.

- Victoria J. Baker, Anthony Jackson, Anthropology at home, ASA monographs 25, London: Tavistock Publications, 1987, 221 pages. - Thomas Bargatzky, Martin A. van Bakel, Private politics; A multi-disciplinary approach to ‘Big-Man’ systems, Studies in Human Society, Vol. I, Leiden: E.J. Brill, 1986. x, 220 pp., illustrations, maps, index., Renée R. Hagesteijn, Pieter van de Velde (eds.) - W.E.A. van Beek, Victor W. Turner, The anthropology of experience, (with an epilogue by Clifford Geertz). Urbana and Chicago: University of Illinois Press, 1986., Edward M. Bruner (eds.) - W. van den Broeke, H. Meyer, De Deli Spoorweg Maatschappij; Driekwart eeuw koloniaal spoor, Zutphen: Walburg Pers, met medewerking van F.A.J. Heckler. 1987; 152 blz. - R. Buijtenhuijs, S. Bernus et al., Le fils et le neveu: Jeux et enjeux de la parenté tourarègue, Cambridge University Press, Cambridge/Editions de la Maison des Sciences de l’Homme, Paris, 1986, XI, 343 pp. - R. Buijtenhuijs, Dominique Casajus, La tente dans la solitude: La société et les morts chez les Touaregs Kel Ferwan, Cambridge University Press, Cambridge/Editions de la Maison des Sciences de l’Homme, Paris, 1987, 390 pp. - H.J.M. Claessen, Christine Ward Gailey, Kinship to kingship; Gender hierarchy and state formation in the Tongan Islands. Austin: University of Texas Press (Texas Press Sourcebooks in Anthropology, No. 14.), 1987. 326 pp., figs., index, bibl. - Alfred E. Daniëls, Richard B. Davis, Muang metaphysics, Bangkok: Pandora Press,1984. - Alfred E. Daniëls, Gehan Wijeyewardene, Place and emotion in northern Thai ritual behaviour, Bangkok: Pandora Press, 1986. - P.M.H. Groen, Jacques van Doorn, The process of decolonization 1945-1975; The military experience in comparitive perspective, CASP publications no. 17, Erasmus Universiteit Rotterdam, 1987, 46 pp., Willem J. Hendrix (eds.) - Rosemarijn Hoefte, Luis H. Daal, Antilliaans verhaal. Zutphen: De Walburg Pers, 1988, Ted Schouten (eds.) - W.L. Idema, Claudine Salmon, Literary migrations; Traditional Chinese fiction in Asia (17th-20th centuries), Beijing: International culture publishing corporation, 1987, 11 + vi + 661 pp. - P.E. de Josselin de Jong, Sharon A. Carstens, Cultural identity in Northern Peninsular Malaysia, Athens, Ohio: Ohio University Monographs in international studies, Southeast Asia series no. 63, 1986. 91 pp. - P.E. de Josselin de Jong, Robert Wessing, The soul of ambiguity: The tiger in Southeast Asia. Northern Illinois University, Center for Southeast Asian studies, Special report no. 24, 1986. 148 pp., glossary, bibliography. - G.W. Locher, Martine Segalen, Historical anthropology of the family, Cambridge University Press, 1986, 328 pp. - Bernd Nothofer, Hans Kähler, Enggano-Deutsches Wörterbuch. Aus dem Nachlass herausgegeben und mit einem Deutsch-Enggano-Wörterverzeichnis versehen von Hans Schmidt, Veröffentlichungen des Seminars für Indonesische und Südseesprachen der Universität Hamburg, Band 14, Berlin: Dietrich Reimer Verlag, 1987. XIII + 404 pp. - J.D.M. Platenkamp, Brigitte Renard-Clamagirand, Marobo; Une société ema de Timor. Langues et civillisations de l’Asie du sud-est et du monde insulindien no. 12, Paris: Selaf, 1983, 490 pp. - H.C.G. Schoenaker, Leo Frobenius, Ethnographische Notizen aus den Jahren 1905 und 1906; II: Kuba, Leele, Nord-Kete; III: Luluwa, Süd-Kete, Bena Mai, Pende, Cokwe. Bearb.u.hrsg. von Hildegard Klein. Wiesbaden: Franz Steiner Verlag, 1987; 1988. 223 S., 437 Zeichnungen, 11 fotos, 5 karten; 268 S., 500 Zeichnungen, 15 fotos, 12 karten. - M. Schoffeleers, I.M. Lewis, Religion in context: Cults and charisma, Cambridge: Cambridge University Press, 1986, X + 139 pp. - B. Schuch, Ingrid Liebig-Hundius, Thailands Lehrer zwischen ‘Tradition’ und `Fortschritt’; Eine empirische Untersuchung politisch-sozialer und pädagogischer Einstellungen thailändischer Lehrerstudenten des Jahres 1974. Beiträge zur Südasienforschung, Band 85, Weisbaden: Steiner Verlag, 1984, 342 pp. - Henke Schulte Nordholt, S.J. Tambiah, Thought and social action; An anthropological perspective, Cambridge, Massachusetts: Harvard Univ. Press, 1985, 411 pp. - Nico G. Schulte Nordholt, Shamsul Amri Baharuddin, From British to Bumiputra rule: Local politics and rural development in Peninsular Malaysia, Singapore: Institute of Southeast Asian studies, 1986. 282 pp. - A. Teeuw, I. Syukri, History of the Malay kingdom of Patani - Sejarah Kerajaan Melayu Patani, by Ibrahim Syukri (pseudonym), translated by Conner Bailey and John N. Miksic. Athens, Ohio: Ohio University Center for International studies, monographs in international studies Southeast Asia series number 68, 1985. xx + 90 pp. - Truong Quang, Andrew Vickerman, The fate of the peasantry: Premature `transition to socialism’ in the democratic republic of Vietnam, Monograph No. 28, Yale University, Southeast Asia studies, 1986. 373 pp., incl. bibliography. - Adrian Vickers, H.I.R. Hinzler, Catalogue of Balinese manuscripts in the library of the University of Leiden and other collections in the Netherlands, vol. I: Reproductions of the drawings from the Van der Tuuk collection; vol. II: Descriptions of the Balinese drawings form the Van der Tuuk collection. Leiden: E.J. Brill/Leiden University Press, 1987.