1.
Jin, Yunkai, et al.
(författare)
New Energy Crops for Biofuel Production
2015
Ingår i: Handbook of clean energy systems. - Chichester, UK : John Wiley & Sons, Ltd. - 9781118388587 ; , s. 49-62
Bokkapitel (refereegranskat)
2.
Nemesio Gorriz, Miguel
(författare)
Molecular responses against Heterobasidion annosum s.l. in Picea abies
2015
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Norway spruce [Picea abies (L.) Karst.] is a main tree species in European forests and is important both ecologically and economically. The root rot fungus Heterobasidion annosum sensu lato (s.l.) is the main P. abies pathogen. Including resistance in breeding programs would help mitigating the impact of the pathogen but knowledge regarding defense mechanisms in P. abies needs a better understanding. The work within this thesis intended to expand the existing knowledge on P. abies resistance mechanisms focusing on hormone signaling, flavonoid biosynthesis and its transcriptional regulation. I found that jasmonic acid is the major hormone controlling defense signaling pathways in P. abies. Furthermore, we validated a candidate gene, PaLAR3, as a resistance marker for H. annosum s.l. in P. abies. PaLAR3 encodes an enzyme responsible for the synthesis of (+) catechin, which showed a fungistatic effect on H. parviporum. Analysis of genetic diversity revealed two allelic lineages of PaLAR3 that showed significant differences in fungal resistance and (+) catechin content that were explained by dissimilarities in inducibility. We studied the role of PaNAC03, a transcription factor that is associated with H. annosum s.l. infection. PaNAC03 not only showed repression of multiple genes including PaLAR3, but bound only to the promoter of one of the PaLAR3 allelic lineages explaining at least partly the differences in allelic expression that were observed. Finally, we identified a full repertoire of members of a MYB/bHLH/WDR transcription factor complex in Norway spruce, which showed differences in protein interactions and expression patterns, and also in ability to control the expression of genes in the flavonoid biosynthetic pathway including PaLAR3.
3.
Ortiz Rios, Rodomiro Octavio
(författare)
Advances in Host Plant and Rhizobium Genomics to Enhance Symbiotic Nitrogen Fixation in Grain Legumes
2015
Ingår i: Advances in Agronomy. - : Elsevier. - 0065-2113 .- 2213-6789. ; 129, s. 1-116
Forskningsöversikt (refereegranskat) abstract
Legumes form symbiotic relationship with root-nodule, rhizobia. The nitrogen (N2) fixed by legumes is a renewable source and of great importance to agriculture. Symbiotic nitrogen fixation (SNF) is constrained by multiple stresses and alleviating them would improve SNF contribution to agroecosystems. Genetic differences in adaptation tolerance to various stresses are known in both host plant and rhizobium. The discovery and use of promiscuous germplasm in soybean led to the release of high-yielding cultivars in Africa. High N2-fixing soybean cultivars are commercially grown in Australia and some countries in Africa and South America and those of pea in Russia. SNF is a complex trait, governed by multigenes with varying effects. Few major quantitative trait loci (QTL) and candidate genes underlying QTL are reported in grain and model legumes. Nodulating genes in model legumes are cloned and orthologs determined in grain legumes. Single nucleotide polymorphism (SNP) markers from nodulation genes are available in common bean and soybean. Genomes of chickpea, pigeonpea, and soybean; and genomes of several rhizobium species are decoded. Expression studies revealed few genes associated with SNF in model and grain legumes. Advances in host plant and rhizobium genomics are helping identify DNA markers to aid breeding of legume cultivars with high symbiotic efficiency. A paradigm shift is needed by breeding programs to simultaneously improve host plant and rhizobium to harness the strength of positive symbiotic interactions in cultivar development. Computation models based on metabolic reconstruction pathways are providing greater insights to explore genotype–phenotype relationships in SNF. Models to simulate the response of N2 fixation to a range of environmental variables and crop growth are assisting researchers to quantify SNF for efficient and sustainable agricultural production systems. Such knowledge helps identifying bottlenecks in specific legume–rhizobia systems that could be overcome by legume breeding to enhance SNF. This review discusses the recent developments to improve SNF and productivity of grain legumes.
4.
Ortiz Rios, Rodomiro Octavio
(författare)
Application of genomics assisted breeding for generation of climate resilient crops: progress and prospects
2015
Ingår i: Frontiers in Plant Science. - : Frontiers Media SA. - 1664-462X. ; 6
Tidskriftsartikel (refereegranskat) abstract
Climate change affects agricultural productivity worldwide. Increased prices of food commodities are the initial indication of drastic edible yield loss, which is expected to increase further due to global warming. This situation has compelled plant scientists to develop climate change-resilient crops,which can withstand broad-spectrums tresses such as drought, heat, cold, salinity, flood, submergence and pests, thus helping to deliver increased productivity. Genomics appears to be a promising tool for deciphering the stress responsiveness of crop species with adaptation traits or in wild relatives toward identifying underlying genes, alleles or quantitative trait loci. Molecular breeding approaches have proven helpful in enhancing the stress adaptation of crop plants, and recent advances in high-throughput sequencing and phenotyping platforms have transformed molecula rbreeding to genomics-assisted breeding (GAB). In view of this, the present review elaborates the progress and prospects of GAB for improving climate change resilience in crops, which is likely to play an ever increasing role in the effort to ensure global food security.
5.
Ortiz Rios, Rodomiro Octavio
(författare)
Plant Breeding in the Omics Era
2015
Bok (refereegranskat) abstract
The field of plant breeding has grown rapidly in the last decade with breakthrough research in genetics and genomics, inbred development, population improvement, hybrids, clones, self-pollinated crops, polyploidy, transgenic breeding and more. This book discusses the latest developments in all these areas but explores the next generation of needs and discoveries including omics beyond genomics, cultivar seeds and intellectual and property rights. This book is a leading-edge publication of the latest results and forecasts important areas of future needs and applications.
6.
Zhu, Tianqing
(författare)
Regulation of embryo development in Norway spruce by WOX transcription factors
2015
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
In seed plants, the apical-basal axis of the plant body is established during early embryogenesis. Major regulatory genes of the apical-basal axis formation belong to the WUSCHEL-RELATED HOMEOBOX (WOX) gene family of transcription factors. The spatiotemporal expression pattern and the molecular role of the WOX genes has mainly been studied in the angiosperm model plant Arabidopsis (Arabidopsis thaliana). Similar information in conifers is limited. The aim of my thesis has been to characterize WOX genes in Norway spruce (Picea abies) and to elucidate the function of WOX genes expressed during embryo development. We cloned 11 WOX homologs from Norway spruce and examined their phylogenetic relationship to WOX genes from other species. The phylogenetic analyses showed that the major diversification within the WOX gene family took place before the gymnosperm-angiosperm split. PaWOX8/9, PaWOX2 and PaWOX3, which are expressed in embryos, were selected for further studies. PaWOX8/9 and PaWOX2 are highly expressed in early and late embryos, and PaWOX3 is highly expressed in mature embryos. Functional studies were performed in RNAi lines where the genes were down-regulated. Embryos in PaWOX8/9 RNAi lines showed a disturbed apical-basal patterning caused by abnormal orientation of the cell division plane at the basal part of the embryonal mass. In PaWOX2 RNAi lines, vacuolated cells differentiated on the surface of the embryonal mass and the embryos failed to form a proper protoderm. Down-regulation of PaWOX3 disturbed lateral margin outgrowth in cotyledons and needles. Taken together, our results indicate that WOX8/9, WOX2 and WOX3 exert evolutionarily conserved functions during embryo development. We can therefore conclude that the regulatory networks of embryo development are at least partly conserved between angiosperms and gymnosperms.
7.
Ahmadi Afzadi, Masoud
(författare)
Genetic variation in resistance to fungal storage diseases in apple : inoculation-based screening, transcriptomics and biochemistry
2015
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Apple is one of the economically and culturally most important fruit crops and has many health-related benefits. Apple production is, however, sensitive to several fungal diseases including blue mold, caused by Penicillium expansum. Problems are more pronounced in organic production or in countries where postharvest application of fungicides is prohibited. To limit or overcome this problem, many studies have been focused on investigations of the mechanism of resistance/tolerance. No major gene(s) have as yet been identified, but quantitatively inherited traits, some of which are related to fruit texture and content of chemical compounds, have been shown to affect the ability of cultivars to withstand storage diseases. In the present thesis, inter-cultivar variation in terms of resistance to fungal storage diseases was investigated at two locations, i.e. Balsgård in Sweden and Njøs in Norway. The association of harvest date, fruit firmness and softening with lesion decay was investigated on large sets of cultivars. The contribution of four fruit texture-related genes (Md-ACO1, Md-ACS1, Md-Exp7 and Md-PG1) in explaining the fruit texture characteristics was examined. Fruit content of chemical compounds with a potential impact on disease resistance was also investigated, and finally the regulation of apple genes upon fungal infection was studied in order to identify candidate genes responsible for disease resistance. Inoculation-based screening indicated large variation across the investigated cultivars in terms of blue mold and bitter rot susceptibility. Harvest date and softening rate of fruits during storage had a large impact on resistance to fungal diseases, thus cultivars with moderate to firm fruits that soften comparatively little during storage could withstand the fungal infection comparatively well. Softening rate is, in its turn, closely associated with harvest date whereas four fruit texture-related genes had lower predictive power than expected. Quantifying the chemical compounds in the fruit samples revealed that some of these compounds, especially flavonols and procyanidin B2, could contribute to resistance against blue mold, whereas contents of malic acids or total titratable acidity had considerably less impact. Differential expression of FLS, LDOX, and CHS genes involved in biosynthesis of flavonoids and PGIP, TT10, WAK1 and CTL1 genes related to cell wall structure indicate the importance of fruit characteristics and biochemical compounds in the resistance mechanism.
8.
Nybom, Hilde, et al.
(författare)
Nordiska äpplen – projekt NordApp
2015
Ingår i: LTV-fakultetens faktablad.
Annan publikation (populärvet., debatt m.m.) abstract
Frukt av många olika slag odlas över hela världen, och utgör en viktig del av den totala livsmedelsförsörjningen. I varmare länder är mångfalden stor – former och färger bildar en förförande palett om man besöker en fruktmarknad, liksom doft och smak hos de frukter man väljer att bekanta sig närmare med. I de nordiska länderna sätter klimatet dessvärre stopp för merparten av dessa frukter – men vi har lyckligtvis några, främst kärn- och stenfrukter inom familjen Rosaceae. Äpple har sålunda odlats i de nordiska länderna sedan början av medeltiden, och detta är numera vår i särklass viktigaste frukt, såväl kulturellt som ekonomiskt. Vissa utländska äpplesorter fungerar ganska bra i odling även på våra breddgrader men för merparten blir den korta vegetationsperioden och de stränga vintrarna övermäktiga hinder. Offentligt finansierade växtförädlingsprogram har därför bedrivits i Finland, Norge och Sverige för att ta fram klimatanpassade sorter. På senare tid har ökad omsorg om miljö och hälsa aktualiserat ytterligare ett förädlingsmål: resistens mot olika skadegörare.
9.
Nybom, Hilde, et al.
(författare)
Resistens mot grönmögel hos äpple
2015
Ingår i: LTV-fakultetens faktablad.
Annan publikation (populärvet., debatt m.m.) abstract
Äpple är gott och nyttigt, och allt fler konsumenter frågar efter svensk frukt i affärerna. Men tillgången är inte så stor eftersom svenska odlare endast producerar 20% av de äpplen vi äter i Sverige. Resten importeras från utlandet, där klimatet är gynnsammare, arbetskostnaderna lägre och tillgången på tillåtna växtskyddsmedel större. Konsumenterna är kanske beredda att betala lite extra för svensk frukt men man förväntar sig då att kvaliteten ska vara på topp: vackra, friska och välsmakande frukter!
10.
