Characterization of Metal Tolerance Proteins and Functional Analysis of GmMTP8.1 Involved in Manganese Tolerance in Soybean

Manganese is an essential micronutrient for plant growth but can be toxic to plants when it reaches excessive levels. Although metal tolerance proteins (MTPs), which belong to the cation diffusion facilitator (CDF) family, have been demonstrated to play critical roles in manganese (Mn) tolerance in plants, the characteristics and functions of GmMTP members in the response of soybean (Glycine max) to Mn toxicity have not been documented. In this study, growth inhibition was observed in soybean plants that were exposed to a toxic level of Mn in hydroponics, as reflected by the generation of brown spots, and decreased leaf chlorophyll concentration and plant fresh weight. Subsequent genome-wide analysis resulted in the identification of a total of 14 GmMTP genes in the soybean genome. Among these GmMTPs, 9 and 12 were found to be regulated by excess Mn in leaves and roots, respectively. Furthermore, the function of GmMTP8.1, a Mn-CDF homologue of ShMTP8 identified in the legume Stylosanthes hamata that is involved in Mn detoxification, was characterized. Subcellular localization analysis showed that GmMTP8.1 was localized to the endoplasmic reticulum (ER). Heterologous expression of GmMTP8.1 led to the restoration of growth of the Mn-hypersensitive yeast (Saccharomyces cerevisiae) mutant Δpmr1, which is made defective in Mn transport into the Golgi apparatus by P-type Ca/Mn-ATPase. Furthermore, GmMTP8.1 overexpression conferred tolerance to the toxic level of Mn in Arabidopsis (Arabidopsis thaliana). Under excess Mn conditions, concentrations of Mn in shoots but not roots were decreased in transgenic Arabidopsis, overexpressing GmMTP8.1 compared to the wild type. The overexpression of GmMTP8.1 also led to the upregulation of several transporter genes responsible for Mn efflux and sequestration in Arabidopsis, such as AtMTP8/11. Taken together, these results suggest that GmMTP8.1 is an ER-localized Mn transporter contributing to confer Mn tolerance by stimulating the export of Mn out of leaf cells and increasing the sequestration of Mn into intracellular compartments.

Clearing confusion in Stylosanthes taxonomy. 3. S. hamata sensu stricto vs. S. hamata sensu lato

Stylosanthes hamata (L.) Taub., a suffruticose leguminous species with spreading prostrate or ascending stems, is widely distributed in the Caribbean region. It was originally described as Hedysarum hamatum by Linnaeus and later transferred to Stylosanthes by Taubert. To date, chromosome analysis of accessions of S. hamata originating from the Caribbean islands has revealed all to be diploids (2n=20). An accession of a morphologically similar Stylosanthes species, collected near Maracaibo in Venezuela in 1965 and subsequently misidentified as S. hamata, has found application as sown forage on low fertility soils in the subhumid to dry tropics since its registration as cultivar Verano in Australia in 1975. This morphotype has been shown to be tetraploid, and has been referred to in the literature as “tetraploid S. hamata” or “S. hamata sensu lato”. More recent work has demonstrated that the tetraploid is in fact an allotetraploid with S. hamata sensu stricto and S. humilis Kunth as the putative diploid progenitors. Various authors have recommended that the allotetraploid be treated as a separate species. We support this recommendation and suggest that, based on the information provided in this paper, the new species be described and validly published following examination of a more exhaustive range of specimens.

The New Putative Type III Effector SkP48 in Bradyrhizobium sp. DOA9 is Involved in Legume Nodulation

Bradyrhizobium sp. DOA9 can nodulate a wide spectrum of legumes; however, unlike other bradyrhizobia, DOA9 carries a symbiotic plasmid harboring type III secretion system (T3SS) and several effector (T3E) genes, one of which encodes a new putative type III effector—SkP48. Here, we demonstrated the pivotal roles of SkP48 from Bradyrhizobium sp. DOA9 in inhibiting nodulation of various Vigna species and Crotalaria juncea and suppressing nodulation efficiency of Arachis hypogea. By contrast, the nodulation efficiency of a SkP48 mutant did not differ significantly with the DOA9 wild-type strain on Macroptilium atropurpureum and Stylosanthes hamata. An evolutionary analysis revealed that the SkP48 effector which contains a shikimate kinase and a SUMO protease (C48 cysteine peptidase) domain is distinct from the others effectors previously identified in others bradyrhizobia and pathogenic bacteria. Our findings suggest that the new putative T3E SkP48 is a key factor suppressing nodulation and nodule organogenesis in several legumes by activation of effector-triggered immunity through salicylic acid biosynthesis induction, which is deleterious to rhizobial infection. In addition, nodulation may be modulated by the function of defensins involved in jasmonic acid signalling in V. radiata SUT1.

The ratio of roughage to concentrate on milk secretion rate in goats fed Stylosanthes ha mata hay

An experiment was conducted to evaluate the effect of roughage to concentrate ratio (R:C) on milk secretion rate (g/h) in goats using a cross-over design in which each goat passed sequentially through all the treatments in random order. The treatments (R: C) were: A = 70 percent roughage : 30 percent concentrate; B = 50 percent roughage : 50 percent concentrate e and C = 30 percent roughage : 70 percent concentrate. In the experiment, seven goats were milked once a day, from the 2nd to 8th week of lactation, thrice per week for 2 weeks per treatment. The animals were fed at 4 percent body weight (DM basis). The feed consisted of Stylosanthes hamata hay (S. hamata hay) and a 17.2 percent CP concentrate ration. Data were analysed using the treatments as main effect with live weight and week of lactation as covariates. There was no significant treatment effects on mülk secretion rate (P>0.05). Overall milk secretion rate was 5.23gh. Week of lactation also had no significant effect (P>0.05). However, live weight of doe at time of milking had a highly significant effect (P>0.001) with milk secretion rate increasing by 0.41g/h per kilogram live weight. The R2 values for the predictive mathematical relationship for goats fed Stylosanthes hamata hay at 4 percent body weight in the dry season was R2 = 0.888. It can therefore be deduced that for a ladating doe in the 5th week of lactation at 20kg body weight fed at 4 percent with Stylosanthes hamata hay to concentrate ratio at 70 percent roughage : 30 percent concentrate would give a milk secretion rate of 6.717g/h while at 50 percent roughage : 50 percent concentrate it would give 6.662 g/h and 30 percent roughage : 70 percent concentrate level would give 7.054 g/h. Keywords:,,,

Ruminal evaluation of nutrient profiles of some legume forages, agricultural by-products and Baobab bark in sheep

The crude protein (CP) ether extract (EE), acid detergent fibre, (ADF), neutral detergent fibre (NDF), Calcium (Ca), Phosphorus (P), Magnesium (Mg) and Copper (Cu) degradability profiles of two legume forages (Tephrosia bracteolata and Stylosanthes hamata), two agricultural by-products (wheat ofsal and Rice bran) and Adansonia digitata (Baobab) bark that usually form part of feed materials commonly used in compounding small ruminant concentrate seed were estimated using nylon-bag technique, based on 5x 5 factorial arrangements in randomized complete block design in 2-way classification Factor A was the different feedstuffs (Tephrosia, Stylo, Baobak bark, Whear offal and Rice bran) while factor B was the different incubation periods (0, 6, 12, 24 and 48h) using individual animal as replicate. Results indicated that as incubation periods increased, the extent of disappearance of the test nutrients of each sample increased while the rate of degradation of each sample varied according/y: The trends of the extent of nutrient disappearance were in the following order: CP: Tephrosia (15.2 +0.14%) > Wheat offal (13.10+0.13%) > Stylo (12.24+0.36)> Rice bran (5.76 + 0.09%) > Baobab bark (3.05 +0.33%) EE: Stylo (9.53 + 0.2296) > Rice bran (5.74 +0.27%) > Wheat offal (2.13 +0.34%)= Baobab bark /2.13 + 0.33%)> Tephrosia (0.35 +0.7394). ADF: Rice bran (53.94 + 7.21%)> Baobab bark (46.87 + 5.34%)> Stylo (34.37+3.07%)> Tephrosia (31.01+4.46%)>Wheat offal (27.50 + 2.0896). NDF: Rice bran (58.11+6.29%)>Baobab bark (47.26+7.12%)>Tephrosia (44.14+3.05%)>Stylo (40.46+3.2296)>Wheat offal (25.29+4.21%) Ca: Tephrosia (0.855+0.18%)> Stylo (0.843+0.19%)> Rice bran (0.308+0.09%)> Wheat offal (0.204+0.04%)>Baobab bark (0.140+0.09%). P: Wheat offal (3.09+0.26%)> Rice bran (1.95+0,10%)> Baobab bark (0.76+0.21%)>Stylo (0.45+0.19%)> Tephrosia (0.09+0.01%). Mg: Tephrosia (0.495+0.31%)>Rice bran (0.234+0.21%)>Wheat offal (0.179+0.30%)>Stylo (0.160+0.23%)>Baobab bark (0.1/6+0.23%) Cu! Stylo (46.65+8. 1796)>Rice bran (37.79+4.7%)>Baobab hark (26.89+2.6%)>Tephrosia (18.51+2.70%)>Wheat ofsal (11.44+2.8%). Baobab bark was the least and slowest in the extent and rate of nutrients released into the rumen. Rice bran was also the second highest in terms of fast release of EE, P, Mg and Cu into the rume, suggesting that it can supply a reasonable level of EE, P, Mg and Cu, in addition to fastest release of +DF and NDF when fed or included in the concentrate supplement for ruminants. Wheat offal is also reasonably rich in crude protein and phosphorus. The two agricultural by-products are therefore good sources of nutrients for ruminants. The two legume forages (Tephrosia and Stylo) are fairly richer in CP, EE, Ca, Mg and Cw than other feedstuffs and they readily released their nutrients faster, and to a larger extent, than other feedstuffs. The inclusion of the two forages in the concentrate supplement, or fed as hay or silage can therefore be recommended in ruminant production, particularly when fast release of the nutrients is required while Baobab bark can be recommended when slow release of nutrient will be beneficial to the requirement of the animal

Performance of Rabbits Fed Stylo (Stylosanthes hamata) and Groundnut Hauls (Arachis hypogea)

Forty eight crossbred rabbits were used to study the performance of different age groups of rabbits fed stylo and groundnut haulms supplemented with 50g concentrate. The rabbits were allocated to three treatments: Stylosanthes hamata (stylo), Arachis hypogea (groundnut) haulms and 50.50 mixture (stygnut) of stylo and groundnut haulms, and four age groups: weaner, grower pubertal and adult in a 3 x 4 factorial experiment in a randomized complete block design for six weeks. 150g forage and 50g concentrate were supplied to the rabbits in separate feeders in the morning at 08. 00hr. Initial and final weight of rabbits fed stylo, groundnut haulms and combination of stylo and groundnut haulms was similar. Concentrate, forage and total feed intake of rabbits were similar for the treatments, however, total weight gain was higher for combination of stylo and groundnut haulms and lowest on stylo. Rabbit performance on sole and combination forages was similar except for feed conversion ratio which was significantly higher for stylo. Though feed cost was similar for the treatments, cost/kg gain was higher for stylo than combination of stylo and groundnut haulms. For the rabbit groups, concentrate, forage and total feed intake were similar however; total weight gain was double for weaners than growers, pubertal and adult rabbits. Weight gain and feed conversion ratio were significantly higher for weaners than growers, pubertal and adult rabbits. Feed cost and cost/kg gain was significantly higher for adult rabbits than weaners but similar with growers and pubertal rabbits. This study shows the potential of feeding several legumes to rabbits and also implies that studies with feed resources should extend beyond weaner and/or grower phase to give practical insight into the performance of rabbits up to market weight.

Energy partitioning of pregnant and lactating rabbit fed combination of concentrate and stylosanthes hamata hay

The study was carried out to examine energy partitioning of pregnant and lactating rabbit offered levels of concentrate and Stylosanthes hamata hay to ascertain whether it meets their high reproductive and nutritional requirement. Forty-eight nulliparous crossbred does (New Zealand White x California and California x Chinchilla breeds) of eight months old were allocated to four dietary treatments in a completely randomised design. During gestation, 150 g/doe/day concentrate and Stylosanthes hamata hay combinations (30:120g, 60:90g, 90:60g and 120:30g) was offered while 350 g/doe/day concentrate and Stylosanthes hamata hay combinations (70:280g, 140:210g, 210:140g and 280:70g) was offered during lactation. Estimations of digestible energy during pregnancy and lactation were carried out and reference data were used to calculate forDE DE DE DE BalanceDE and DE /LW0.75. req, m, fg, macc, req Results obtained showed non-significant (P>0.05) difference among 90:60 and 120:30% concentrate and Stylosanthes hamata hay combinations in terms of DM DE DE DE intake, intake, req, fg, DE BalanceDE and DE /LW0.75, but were significantly (P<0.05) higher than 30:120 and macc, req 60:90% concentrate and Stylosanthes hamata hay combinations. Rabbit in the 4th week of pregnancy had significantly (P<0.05) higher DE DE DE DE BalanceDE and intake, req, fg, macc, DE /LW0.75 than does in the 2nd week of pregnancy. During lactation, all parameters showed req non-significant (P>0.05) difference. Therefore, the diet combinations were sufficient to provide adequate digestible energy for the physiological needs of does during pregnancy and lactation.

Energy partitioning for growth by rabbits fed groundnut and stylo santhes forages supplemented with concentrate

Forty eight crossbred (California X New Zealand White) rabbits were used to evaluate energy partitioning of rabbits fed forages supplemented with concentrate. The rabbits were randomly allocated to three treatments consisting of sole Stylosanthes hamata (stylo),sole Arachis hypogea (groundnut) haulms and 50:50 mixture of both forages (mixed), and four class groups: weaners, 6-8 weeks old (0.79kg), growers, 11-12 weeks old (1.15kg), pubertal, 15-16 weeks old (1.36kg) and adult, >16 weeks old (1.55kg) in a completely randomized design (3 x 4 factorial experiment). The rabbits were individually housed and offered 150g forage and 50g concentrate diet in separate feeders at 08.00hr. Feeding sole or mixed forages did not significantly affect daily gain or body composition of rabbits. DE intake, DE retention as protein, fat and growth, DE requirement for maintenance, protein synthesis, fat synthesis and for growth were similar for sole and mixed forages. Efficiency of utilization of DE for growth was significantly higher for mixed forage than sole stylo and ranged between 0.41-0.43. DE intake was similar for all classes of rabbits. Weaners had significantly higher retained energy as protein, fat and growth, DE requirement for protein and fat synthesis and for growth and efficiency of DE utilization for growth than growing, pubertal and adult rabbits. Efficiency of DE utilization for growth ranged between 0.39-0.47. Retained energy as protein, fat and for growth were similar for weaner and grower rabbits on mixed forage but higher than for pubertal and adult rabbits. For sole stylo, weaner rabbits retained more energy as protein, fat and growth than grower, pubertal and adult rabbits while for sole groundnut haulms, weaner and pubertal rabbits retained more energy as protein, fat and growth than grower and adult rabbits. DE utilization was better for mixed than stylo. It is concluded that feeding a mixture of groundnut and stylo forages slightly increased gain and improved efficiency of DE utilization resulting in better performance of the rabbits.

Effet de l’insertion des plantes de couverture sur la productivité du système de culture à base de maïs dans le cadre de l’intégration agriculture-élevage

En zone soudano-sahélienne, la productivité des cultures est limitée par les effets néfastes du changement climatique et la pauvreté des sols. L’insertion des plantes de couverture dans les systèmes de production pourrait être une alternative d’amélioration des rendements et de la biomasse. Pour atteindre cet objectif, la pratique conventionnelle de la culture du maïs a été comparée pendant cinq années (2014-2018), à quatre systèmes de culture associant des plantes de couverture. Le dispositif expérimental utilisé a été un bloc de Fisher avec 6 traitements en 4 répétitions. Les résultats ont montré que l’insertion du Cajanus cajan, du Stylosanthes hamata, du Brachiaria ruziziensis et Mucuna cochinchinensis dans un système de culture à base du maïs permet d’améliorer la production de biomasse fourragère sans négativement affecter son rendement. Utilisée dans la supplémentation des animaux, la biomasse produite peut nourrir pendant 90 jours 7 unités de bétail tropical (UBT) en culture pure du maïs et 8 à 13 unités de bétail tropical (UBT) en fonction du type de plantes de couverture. Dans le cadre de la production fumure organique, les mêmes tendances de variations ont été obtenues en fonction des systèmes de culture. L’insertion des plantes de couverture est un élément intégrateur agriculture-élevage.Mots clés : Changement climatique, maïs, légumineuse, biomasse fourragère, zone Soudano-sahélienne, Mali English Title: Cover crop insertion effect on productivity of maize-based cropping system in the context of crop-livestock integrationIn Sudano-Sahelian zone, crop productivity is limited by climate change effect and poor soils. Inserting cover crops into production systems could be an alternative to improve yields and biomass. To achieve this goal, conventional practice of maize cultivation was compared over a five-year period (2014-2018) with four cropping systems using cover crops. The experimental design used was a Fisher block with 6 treatments in 4 replicates. The results showed that the insertion of Cajanus cajan, Stylosanthes hamata, Brachiaria ruziziensis and Mucuna cochinchinensis in a maize-based cropping system improves biomass production without negatively affecting its yield. Used in animal supplementation, the biomass produced can feed 7 Tropical Livestock Units (UBT) of pure maize crop and 8 to 13 UBT for 90 days, depending on the type of cover crop. In the case of organic manure production, the same variations were obtained depending on cropping systems. The insertion of cover crops in cropping system is an integrating agriculture-livestock component.Keywords: Climate change, maize, legumes, fodder biomass, fodder biomass, Sudano-Sahelian zone, Mali.

Optimisation de l'utilisation du Panicum maximum C1 Aeschynomene histrix, Stylosanthès hamata et, Arachis pintoï sur les performances zootechniques des lapins

Au Burkina Faso l’alimentation des animaux pendant la saison sèche constitue le premier contraint du développement de l’élevage. Cette étude a pour but d’évaluer l’effet d’une alimentation à base de Panicum maximum C1, Aeschynomene histrix, Stylosanthès hamata, Arachis pintoï sur les performances zootechniques des lapins. Le dispositif expérimental a été réalisé sur la Station de Recherche de Farako-Bâ. Au total, neuf (9) lapins mâles (Oryctolagus cuniculus L.) âgés de dix (10) semaines et pesant en moyenne (790 ± 39,04g) chacun, ont été répartis dans 3 cages de volume: 42 cm x 63 cm x 39 cm soit un volume de 103194 cm3 chacune. Ces lapins ont été répartis en trois (3) lots de trois (3) lapins chacun. Les lots ont reçu les rations suivantes: la ration1du lot1(R1L1) était composée de l’aliment Panicum maximum C1, Aeschynomene histrix ; la ration 2 (R2L2), Panicum maximum C1, Stylosanthès hamata et la ration 3 (R3L3), Panicum maximum C1, Arachis pintoï. A chaque ration on a ajouté du son de maïs et de riz et du sel. Les lapins nourris à la ration R3L3, ont eu un gain moyen journalier de 9,13±4,33 g/j contre 8,51±2,22g/j pour R1L1 8,90±3,33g/j pour R2L2. Une différence non significative (p > 0,05) est observée entre les trois rations. La ration R3L3 donne de bonnes performances zootechniques et constitue un atout économique pour les cunicultures.Mots clés : lapins, rations, gain moyen quotidien, alimentation English title: Optimization of the use of Panicum maximum C1 and Aeschynomene histrix, Stylosanthes hamata and, Arachis pintoï on the zootechnical performance of rabbitsIn Burkina Faso feeding animals during the dry season is the main constraint on livestock development. This study aims to evaluate the effect of a diet based on Panicum maximum C1, Aeschynomene histrix, Stylosanthès hamata, and Arachis pintoï on the zootechnical performance of rabbits. The experimental device was carried out at the Farako-Bâ Research Station. A total of nine (9) male rabbits (Oryctolagus cuniculus L.) aged ten (10) weeks and weighing on average (790 ±39,04g) each, were distributed in three volume cages: 42 cm x 63 cm x 39 cm, each having a volume of 103194 cm3. These rabbits were divided into three (3) lots of three (3) rabbits each. The lots received the following rations: ration1 of Lot 1(R1L1) consisted of the food Panicum maximum C1 and Aeschynomene histrix; ration 2 (R2L2), Panicum maximum C1 and Stylosanthès hamata and ration 3 (R3L3), Panicum maximum C1, Arachis pintoï. Corn and rice bran and salt was added to each ration. Rabbits fed R3L3, had an average daily gain of 9,13±4,33 g/d compared to 8,51±2,22g/d for R1L1 and 8,90±3,33g/d for R2L2. There was no difference between the three rations (p > 0.05) but the R3L3 ration provides good zootechnical performance and is an economic asset for cuniculture.Keywords: Rabbits, rations, average daily gain, feed.