Structure and Expression of a Dhurrinase (β-Glucosidase) from Sorghum

Sorghum (Sorghum bicolor L. Moench) has two isozymes of the cyanogenic β-glucosidase dhurrinase: dhurrinase-1 (Dhr1) and dhurrinase-2 (Dhr2). A nearly full-length cDNA encoding dhurrinase was isolated from 4-d-old etiolated seedlings and sequenced. The cDNA has a 1695-nucleotide-long open reading frame, which codes for a 565-amino acid-long precursor and a 514-amino acid-long mature protein, respectively. Deduced amino acid sequence of the sorghum Dhr showed 70% identity with two maize (Zea mays) β-glucosidase isozymes. Southern-blot data suggested that β-glu-cosidase is encoded by a small multigene family in sorghum. Northern-blot data indicated that the mRNA corresponding to the cloned Dhr cDNA is present at high levels in the node and upper half of the mesocotyl in etiolated seedlings but at low levels in the root—only in the zone of elongation and the tip region. Light-grown seedling parts had lower levels of Dhr mRNA than those of etiolated seedlings. Immunoblot analysis performed using maize-anti-β-glucosidase sera detected two distinct dhurrinases (57 and 62 kD) in sorghum. The distribution of Dhr activity in different plant parts supports the mRNA and immunoreactive protein data, suggesting that the cloned cDNA corresponds to the Dhr1 (57 kD) isozyme and that the dhr1 gene shows organ-specific expression.     

Biochemical Characterisation and Cloning of α-Kafirin Gene from Sorghum (Sorghum bicolor L Moench)

Seed storage proteins from naturally occurring lysine-rich cultivars namely IS 217O₂, CVS 365, G 1058, G 205 and CVS 549 were analyzed biochemically, immunologically and compared with a low-lysine cultivar (White Martin) and a chemically induced high-lysine mutant (P7210). Protein fractionation studies indicated that the high lysine cultivars contained 25% less kafirin and an increased alcohol insoluble reduced glutelin without affecting the total protein content. SDS-PAGE analysis of total kafirin showed the absence of 25.3 kD and 25.9 kD a-kafirin proteins in lysine-rich cultivars IS 217O₂, CVS 365 and G 1058, while in G 205 only the 25.9 kD protein was absent compared to low-lysine cultivar White Martin. A genomic clone λGK5 encoding an a-kafirin has been isolated from cv White Martin genomic library using pSKR3 as hybridizing probe and sequenced. Transient expression studies by particle bombardment of immature seeds of sorghum allowed to detect β-glucuronidase (GUS) activity only in endosperm cells confirming that the α-kafirin gene promoter is functional and tissue specific.     

Evaluation of Sweet Sorghum and Sorghum × Sudangrass Hybrids as Feedstocks for Ethanol Production

Field studies were conducted at the USDA-ARS Sugarcane Research Laboratory in southeast Louisiana to evaluate the ethanol yield potential of five sweet sorghums (Dale, M81-E, Rio, Theis, and Topper) and two non-flowering sorghum × sudangrass forage hybrids (MMR 333/27 and MMR 333/47). The sorghums were planted in the spring and harvested at 85, 101, 119, and 138 days after planting (DAP). Theoretical sugar-based ethanol yield increased for the sweet sorghums (except Rio) from 85 through 119 days, but did not significantly increase further at 138 days. The forage sorghums did not show a similar increase, though the theoretical sugar-based ethanol yield of MMR 333/47 at 138 DAP was greater than at 85 DAP. Conversely, theoretical fiber-based ethanol yields increased two-fold in the two forage sorghums from 85 to 138 DAP; a significant increase in fiber-based ethanol yield was not observed in any of the sweet sorghums over the same period. At 138 DAP, sugar-based ethanol yield of Theis (6,060 L ha^?1), was greater than that of Rio or either of the two forage hybrids. Fiber-based ethanol yield of MMR 333/47 (8,860 L ha^?1) was greater than that of any other variety in the test. Theoretical ethanol yield from hexose sugar and fiber components averaged across varieties was 6,500, 7,720, 9,100, and 10,810 L ha^?1 at 85, 101, 119 and 138 DAP, respectively. As a complementary crop for Louisiana’s sugarcane growers, sorghum would need to be harvested not later than 120 DAP so as to not interfere with the planting of sugarcane in these fields. Both Theis and MMR 333/47 produced greater than 11,000 L ha^?1 combined theoretical ethanol at 119 DAP, Theis, equally from sugar and fiber, MMR 333/47 about two-thirds from fiber. Choice of sorghum type would depend on the conversion process(s) being used at the biorefinery.     

<Emphasis Type="Italic">Agrobacterium</Emphasis>-mediated transformation of sorghum (<Emphasis Type="Italic">Sorghum bicolor</Emphasis> (L.) Moench) using an improved in vitro regeneration system

An improved regeneration protocol suitable for transformation of sorghum was developed. The improvements focused on limiting the production of phenolic compounds and the use of suitable culture vessels for each developmental stage in plant regeneration from immature embryo derived calli. The addition of activated charcoal in the callus induction medium reduced the production of black pigments, however it also inhibited the callus formation on immature embryo explants. Cold pre-treatment of the immature seeds from which embryo explants were excised had a positive effect on both explant survival and callus formation. A one-day 4°C treatment of immature seeds significantly improved the callus formation from immature embryos and reduced the need for frequent subculture. Petri dishes with ventilation were suitable for the callus induction phase, but not for plant regeneration. Regeneration of plants could be improved by using disposal plastic boxes (250 ml volume) instead of Petri dishes. Agrobacterium-mediated transformation using the improved regeneration protocol and the hygromycin phosphotransferase gene as selectable marker resulted in the recovery of 15 transgenic plants from 300 initial immature embryos (5% efficiency). The transgenic nature of the obtained plants was demonstrated by Southern hybridisation and progeny analysis. The transgenes were inherited in a Mendelian fashion and were integrated at a single locus in the majority of the analysed lines.     

Amino acid profiling of <Emphasis Type="Italic">Sorghum bicolor</Emphasis> vis-à-vis <Emphasis Type="Italic">Chilo partellus</Emphasis> (Swinhoe) for biochemical interactions and plant resistance

Amount of certain amino acids required by herbivores, and their availability in host plants are of crucial importance for insect growth, development, and life processes. Therefore, we carried out profiling and quantification of 17 amino acids in diverse sorghum genotypes, and on the Chilo partellus larvae reared on them, to understand the association and contribution of different amino acids in plant resistance to insects. Sorghum germplasm lines IS 2205 and IS 2123 had severe detrimental effects on the development and survival of C. partellus followed by varieties ICSV 700 and ICSV 708 in comparison to susceptible check, Swarna. Profiling of sorghum seedlings, seeds, and the C. partellus larvae fed on these genotypes for 17 amino acids revealed that Arginine, Glycine, Isoleucine, Leucine, Proline, and Valine in sorghum seedlings and the C. partellus larvae had significant and positive association, suggesting their role in the development and survival, while negative association of Cystine indicated its contribution in plant defense. Furthermore, C. partellus acquired less of cyclic and aliphatic amino acids per unit amount from the test resistant genotypes, while more from the susceptible check, than their presence in the seedlings. Present studies suggest that Alanine, Cystine, Glycine, and Proline contents in C. partellus larvae; Cystine and Proline contents in sorghum seedlings; and Methionine content in sorghum seeds, have significant and negative association, and contribute to explain?>93% and >96%, respectively, of the variability in antibiosis mechanism and overall resistance to C. partellus. These studies have implications for antibiosis and nutritional mechanism of host plant–insect interactions in sorghum against C. partellus.     

Effects of Phosphorus Nutrient on the Hydraulic Conductivity of Sorghum （Sorghum vulgare Pers.） Seedling Roots Under Water Deficiency

Hydroponic experiments were conducted in a growth chamber and changes in the hydraulic conductivity of sorghum (Sorghum vulgare Pers.) roots (Lpr) at the three-leaf stage were measured using the pressure chamber method. Water deficiency was imposed with polyethylene glycol (PEG) 6000 and the phosphorus (P) levels were controlled by complete Hoagland solution with and without P nutrient. The objective of this study was to investigate the effect of P nutrition on root Lpr under water deficiency. The results showed that the Lpr in P deficiency treatments decreased markedly, but the Lpr recovered to the same value as that of control when sufficient P was supplied for 4-24 h. Water deficiency decreased Lpr, but the hydraulic conductivity of the roots with sufficient P supply was still higher than that of plants without P supply. When resuming water supply, the Lpr of the water-deficient plants under P supply recovered faster than that of plants without P supply, which indicates that plants with sufficient P nutrient are more drought tolerant and have a greater ability to recover after drought. The treatment of HgCl2 indicated that P nutrient could regulate the Lpr by affecting the activity and the expression levels of aquaporins.     

Sorghum—Its production,utilization and breeding

A corn-like cereal grass which among its 400 known varieties produces broomcorn, the principal material used in the manufacture of brooms, and important edible grains of Africa and Asia—durra, kafir, milo, shallu, kaoliang, feterita and hegari.     

Identification of QTL for sugar-related traits in a sweet × grain sorghum (<Emphasis Type="Italic">Sorghum bicolor</Emphasis> L. Moench) recombinant inbred population

QTL for stem sugar-related and other agronomic traits were identified in a converted sweet (R9188) × grain (R9403463-2-1) sorghum population. QTL analyses were conducted using phenotypic data for 11 traits measured in two field experiments and a genetic map comprising 228 SSR and AFLP markers grouped into 16 linkage groups, of which 11 could be assigned to the 10 sorghum chromosomes (SBI-01 to SBI-10). QTL were identified for all traits and were generally co-located to five locations (SBI-01, SBI-03, SBI-05, SBI-06 and SBI-10). QTL alleles from R9188 were detected for increased sucrose content and sugar content on SBI-01, SBI-05 and SBI-06. R9188 also contributed QTL alleles for increased Brix on SBI-05 and SBI-06, and increased sugar content on SBI-03. QTL alleles from R9403463-2-1 were found for increased sucrose content and sucrose yield on SBI-10, and increased glucose content on SBI-07. QTL alleles for increased height, later flowering and greater total dry matter yield were located on SBI-01 of R9403463-2-1, and SBI-06 of R9188. QTL alleles for increased grain yield from both R9403463-2-1 and R9188 were found on SBI-03. As an increase in stem sugars is an important objective in sweet sorghum breeding, the QTL identified in this study could be further investigated for use in marker-assisted selection of sweet sorghum.     

高粱苗(Sorghum vulgare)水分亏缺时所累积的游离脯氨酸的来源

在完全营养液中,用Glu或Ala替代Ca(NO_3)_2为氮源时,在水分胁迫条件下可得到同样程度的Pro累积量。但是用Ser为氮源时,在正常水分条件下Glu和Ala的相对含量较少,Ser和Gln相对含量较高,在水分胁迫条件下,Pro的累积受到抑制。在缺钾营养液中培养时,植株游离氨基酸中Glu和Ala相对量较少,Ser和Gln相对量较高,在水分胁迫条件下,Pro累积也受到抑制。在缺钾营养液中,用Glu或Ala替代Ca(NO_3)_2为氮源时,在水分胁迫条件下Pro的累积可达到甚至超过完全营养液中Pro的相对量。     

PCR Amplification，Cloning and Sequencing of RbcL Coding Region in Mesophyll Cell and Bundle Sheath Cell of Sorghum（Sorghum bicolor L．）

ＰＣＲＡｍｐｌｉｆｉｃａｔｉｏｎ,ＣｌｏｎｉｎｇａｎｄＳｅｑｕｅｎｃｉｎｇｏｆＲｂｃＬＣｏｄｉｎｇＲｅｇｉｏｎｉｎＭｅｓｏｐｈｙｌｌＣｅｌｌａｎｄＢｕｎｄｌｅＳｈｅａｔｈＣｅｌｌｏｆＳｏｒｇｈｕｍ（ＳｏｒｇｈｕｍｂｉｃｏｌｏｒＬ．）ＺＨＡＯＹｉｎ－ｓ...     

Properties of the isoforms of α-amylase from kilned and unkilned malted sorghum (Sorghum bicolor)

We have previously reported the presence of a relatively heat-stable α-amylase with a low K_m for starch in kilned malted sorghum. In order to establish the industrially useful and more efficient isoforms, we have separated this α-amylase into different isoforms using both cation and anion-exchange chromatographies. Unkilned malted α-amylase crude was separated into three different isoforms (a1, a2 and a3) whereas kilned samples were separated into two (a1 and a2). Apparently one isoform (a3) was lost during kilning due to heat lability. a1 isoform which appears to have a neutral pI and constitute about 60% of the total α-amylases protein that were induced during germination, have the lowest K_m for starch. They are more generally stable than other isoforms at all the temperatures studied. These isoforms lost only 10% activity at 80 °C for 30 min and still had some residual activity at 100 °C incubation for 30 min. a1 isoform could therefore be adapted for industrial starch conversion processes which are carried out within this range of gelatinizing temperatures because of its properties.     

Valbro : un nouveau site à vertébrés de l’Oligocène inférieur (MP 22) de France (Quercy). II – Oiseaux (Aves)

The bird remains from Valbro belong only to three taxa, Paraortyx lorteti, Archaeotrogon venustus, and A. zitteli. This association makes it possible to ascribe to this locality an early Oligocene age, reference-levels MP 22 or MP 23, which is in agreement with the age given by the mammals.     

晋杂四号高粱(Sorghum vulgare cv.Jinza4)颖片花色素的分析

通过纸色谱法、光谱法、AlCl_3红移和显色试验,从红高粱颖片的乙醇提取液中分离和鉴定出了5、7、4′—三羟花色(钅羊)和5、7、3′、4′—四羟花色(钅羊)两种花色素。从颖片中还分离出了紫棕色、黄色和淡红色的花色素类。     

高粱(Sorghum bicolor)分子图谱的构建及寄生草(Striga asiatica)萌发诱导物基因的定位

高粱是世界上第五大主要粮食作物,也是非洲国家的主要粮食来源之一,Ｓｔｒｉｇａ ａｓｉａｔｉｃａ是一种寄生于高粱等主要农作物的野生草之一。选用两个对寄生草抗性表现差异的 高粱品系“山桂红”和“ＳＲＮ３９”作亲本,构建了一个重组近交系群体（Ｒｅｃｏｍｂｉｎａｎｔ ｉｎｂｒｅｄ, ＲＩ）,并随机筛选出９４个系用于构建分子连锁图谱和基因定位。在应用的２８６个多态性标记 中,有２５１个标记分别标定在１０条不同的连锁群上,标记间的平均图距为７．１ｃｍ,总图谱覆盖 了高粱基因组的１７７９ｃｍ,是目前国际上几个比较完整的高粱分子连锁图谱之一。群体的共 分离分析表明,与寄生草抗性有关的萌发诱导物基因（Ｇｅｒｍｉｎｉｎａｔｉｏｎ　ｓｔｉｍｕｌａｎｔ　ｇｅｎｅ－ＧｅｒｍＳｔｉｍ） 位于高粱的遗传连锁群Ｊ上,相距较近的分子标记为１３ｃｍ。进一步的精细定位分析,发现有 两个分子标记分别位于基因的两侧,距离为１．６和２．１个ｃｍ。     

On the Fertilization of Oryza sativa L. × Sorghum vulgare Pets.

1.The pollen germination of Sorghum vulgate appeared normal on the stigma of the Oryza sativa, but the pollen tubes grew slowly in the style. Some of the pollen tubes may become enlarged in their tips or sometimes bursting, while others have continued to grow and entered the embryo sacs. 2. The growth rate of the pollen tubes varied widely. A few pollen tubes were observed in the embryo sacs of the materials 2 hours after pollination, but most of them entered the embryo sacs much later. 3. The zygote associated with a paucity of endosperm nuclei was observed in the materials 1 day after pollination. The double fertilization and 8–12-celled proembryo associated with a number of the free nuclei of the endosperm appeared with a rather high frequency (10.3%) in the materials 3 days after pollination. Some of them are normal in appearance and others may show more or less abnormalities. 4. No division figure was found except in one single case in which mitoses have occurred in both the proembryo and the endosperm. It is most likely that in such case the proembryo and the endosperm if left intact might develop further. 5. A 80-celled embryo was the biggest one which appeared in the materials 5 days after pollination. In general, no cells were ever formed in the endosperm, except in one instance among the 7 days materials the endosperm became cellular in micropylar end. In all other cases the endosperm either ceased to develop early or disorganized. The disorganized endosperm materials are considered to be utilized by the embryo. 6. In certain instances the free nuclei of the endosperm were not distributed at random. They were not equal in size and might fuse into giant nuclelei. 7. The most striking feature is that in the embryo sacs, in which double fertilization or proembryo and endosperm have occurred, a dark stained pollen tube was commonly present. This fact leads us to the conviction that in general only if a healthy pollen tube entered the embryo sac, double fertilization can take place and further development can proceed. 8. In certain cases the protoplasm of the embryo cells appeared scanty. It is apparently that the normal metabolism of the embryo was disturbed owing to the lack of nutrient, and the death of the embryo ensued. 9. No differentiated embryo was observed and no mature seeds were produced. The materials fixed 12 days after pollination showed a variety of abnormalities and collapses. The authors believe that the failure of seed production of rice X kaoliang was primarily due to the fact that the pollen tubes in the style grew too slowly to reach the embryo sacs in time. The consequence is that the double fertilization took place only in a late stage while the male and female gametes may have already become unhealthy. In addition, in this late stage the stored starch in the maternal tissues having gradually disappeared, the nutrient supply to the embryo sac was therefore limited and the young embryo and endosperm were finally in starvation.     

The Accumulation of Free Proline and Its Roles in Water-Stressed Sorghum Seedlings

The role of proline has recently been a sub-ject of intensive research. This stems from:(1) the marked accumulation of free prolinein plants undergoing water stress, salinity, lowtemperature, air pollutants, etc. and possibleroles of accumulated proline in plants (Stewart     

A high-density genetic map of Sorghum bicolor (L.) Moench based on 2926 AFLP®, RFLP and SSR markers

Using AFLP technology and a recombinant inbred line population derived from the sorghum cross of BTx623 × IS3620C, a high-density genetic map of the sorghum genome was constructed. The 1713 cM map encompassed 2926 loci distributed on ten linkage groups; 2454 of those loci are AFLP products generated from either the EcoRI/MseI or PstI/MseI enzyme combinations. Among the non-AFLP markers, 136 are SSRs previously mapped in sorghum, and 203 are cDNA and genomic clones from rice, barley, oat, and maize. This latter group of markers has been mapped in various grass species and, as such, can serve as reference markers in comparative mapping. Of the nearly 3000 markers mapped, 692 comprised a LOD 3.0 framework map on which the remaining markers were placed with lower resolution (LOD <3.0). By comparing the map positions of the common grass markers in all sorghum maps reported to date, it was determined that these reference markers were essentially collinear in all published maps. Some clustering of the EcoRI/MseI AFLP markers was observed, possibly in centromeric regions. In general, however, the AFLP markers filled most of the gaps left by the RFLP/SSR markers demonstrating that AFLP technology is effective in providing excellent genome coverage. A web site, http://SorghumGenome.tamu.edu, has been created to provide all the necessary information to facilitate the use of this map and the 2590 PCR-based markers. Finally, we discuss how the information contained in this map is being integrated into a sorghum physical map for map-based gene isolation, comparative genome analysis, and as a source of sequence-ready clones for genome sequencing projects.     

Valbro : un nouveau site à vertébrés de l’Oligocène inférieur (MP22) de France (Quercy). I – Contexte géologique ; Mammalia : Rodentia,Hyaenodontida, Carnivora

The locality Valbro (Quercy, France) has yielded a rich fossil vertebrate fauna. Here are presented the geological context, a preliminary faunal list and the systematics of the Rodentia and carnivores, the most abundant taxa of the fauna. The Rodentia are known from 11 taxa: the Theridomyidae Blainvillimys gregarius Schlosser, 1884, Blainvillimys ?gemellus Vianey-Liaud, 1989, Issiodoromys medius (Vianey-Liaud, 1976) and S. cayluxi Schlosser, 1884, the Aplodontidae Plesispermophilus angustidens Filhol, 1882, the Gliridae Butseloglis tenuis (Bahlo, 1975), Butseloglis micio (Misonne, 1957) and Bransatoglis planus (Bahlo, 1975), the Sciuridae Palaeosciurus goti Vianey-Liaud, 1974 and cf. Oligopetes sp., and the Cricetidae Atavocricetodon sp. aff. A. nanus (Pelaez-Campomanes, 1995). Thirteen taxa of carnivores are present at Valbro; among the Hyaenodontida: Hyaenodon leptorhynchus Laizer et Parieu, 1838 and cf. Apterodon sp.; among the Carnivora: a Feliformia gen. et sp. indet., the Nimravidae Nimravus intermedius (Filhol, 1872), Dinailurictis bonali Helbing, 1922 and Nimravidae gen. et sp. indet. (Certainly belonging to one the two already identified species), the Ursida Pachycynodon crassirostris Schlosser, 1888, Pachycynodon sp., Amphicynodon sp. 1 cf. A. typicus (Schlosser, 1888), Amphicynodon ? sp. 2 and Ursida gen. et sp. indet. cf. Pachycynodon boriei (Filhol, 1876), the Mustelida M. olivieri Bonis, 1997, the Carnivora incertae sedis Palaeogale sectoria (Gervais, 1848–1852), the Arctoidea gen. et sp. indet. and Carnivora gen. et sp. indet. (probably representing taxa already identified at lower taxonomic levels). The evolutionary grade of B. gregarius of Valbro compares to that of the species from Mas de Got, La Plante 2 and Cavalé, which supports an MP22 age for Valbro. This datation is further supported by the association of Theridomyinae yielded by the locality (B. gregarius, B. gemellus, I. medius and S. cayluxi), and by the presence of a N. intermedius that well compares the material of the species from Villebramar, La Plante et Mas de Got, of D. bonali, P. sectoria, M. olivieri (species known only from Mas de Got), and by additional evidence from the remaining vertebrates from Valbro, especially the squamates. Despite a limited amount of specimens (341 specimens have been studied), the faunas of rodents and carnivores from Valbro are the most speciose and diverse known for the MP22 level and, for the Carnivora fauna in particular, for the Oligocene of the Old World.     

Au Gravettien, dans la grotte Cosquer (Marseille, Bouches-du-Rhône), l'Homme a-t-il compté sur ses doigts ?

Negative hands, occasionally with incomplete fingers, are often found in Paleolithic caves but so far have received no definitive explanation. Nowadays they are more commonly seen as the expression of a gestural language. In this paper, we suggest that the negative hands visible in the Cosquer cave and dating from around 27?000 BP could represent counting on fingers. Several arguments are developed to support this hypothesis. Furthermore we also suggest that the dots and dashes often associated with negative hands in numerous caves, might be another, more advanced way of representing numbers.