The Sorghum (Sorghum bicolor) Brown Midrib 30 Gene Encodes a Chalcone Isomerase Required for Cell Wall Lignification

In sorghum (Sorghum bicolor) and other C4 grasses, brown midrib (bmr) mutants have long been associated with plants impaired in their ability to synthesize lignin. The brown midrib 30 (Bmr30) gene, identified using a bulk segregant analysis and next-generation sequencing, was determined to encode a chalcone isomerase (CHI). Two independent mutations within this gene confirmed that loss of its function was responsible for the brown leaf midrib phenotype and reduced lignin concentration. Loss of the Bmr30 gene function, as shown by histochemical staining of leaf midrib and stalk sections, resulted in altered cell wall composition. In the bmr30 mutants, CHI activity was drastically reduced, and the accumulation of total flavonoids and total anthocyanins was impaired, which is consistent with its function in flavonoid biosynthesis. The level of the flavone lignin monomer tricin was reduced 20-fold in the stem relative to wild type, and to undetectable levels in the leaf tissue of the mutants. The bmr30 mutant, therefore, harbors a mutation in a phenylpropanoid biosynthetic gene that is key to the interconnection between flavonoids and monolignols, both of which are utilized for lignin synthesis in the grasses.

Effect of variation of strain rate on the tensile properties of Coconut leaf midrib - A sustainable material for ground improvement

This paper aims at introducing a new natural fibers used as ground improvement material, which enables to improve the engineering properties of poor soil in an economical and sustainable manner. An investigation of extraction procedure of coconut leaf midrib has been undertaken. The study of tensile behavior of ground improvement material with different strain rate is very significant since, the small strain rate study simulates long term loading and large strain rate study simulates impact loading condition. The strain rate chosen for the present study were in terms of percentage of gauge length of specimen per minute. Moreover, the optimum strain rate and characteristic tensile strength of coconut leaf midrib was established by using Weibull parameters.

Restructuring citrus endophytic diversity through potential indigenous endophytes could eliminate huanglongbing pathogen Candidatus Liberibacter asiaticus

Background Huanglongbing (HLB) is a major botanical pandemic of citrus crops caused by Candidatus Liberibacter asiaticus (Clas). It is important to understand the different mechanisms involved in interaction of pathogen with plants to develop novel management strategy against HLB. However, until now there has been no control strategy to manage this disease in vitro and on large scale in citrus grove. We found that, indigenous endophyte Bacillus subtilis L1-21, a patented strain isolated from healthy citrus tree, may have the potential to reduce the impact of pathogen through restructuring of core endophytes. Results A novel half-leaf method was developed to test the efficacy of B. subtilis L1-21 against Clas. Concentration of B. subtilis L1-21 at 104 cfu ml− 1 resulted in a 1000-fold reduction in Clas copy densities per gram of leaf midrib (107 to 104) by 4 d after treatment. With endophytes, where HLB incidence was reduced to < 3% and Clas copy density was reduced from 109 to 104 pathogen g− 1 of diseased leaf midrib. We found that 16 of 93 tree samples became Clas-free and functional pathways and pathogen resistance genes were regulated in diseased citrus trees after treatment. Conclusions This is the first large-scale study using an indigenous endophyte and shows its potential utility in sustainable disease management through strengthening the citrus microbiome.

Anatomical investigations on Turkish critically endangered species: Achillea sivasica Çelik et Akpulat (Asteraceae)

In this study, root, stem, leaf midrib and leaf lamina anatomy and achene micromorphology of Turkish critically endangered endemic Achillea sivasica were investigated for the first time. In this study, the root was found in late primary growth and in early secondary growth stage. It has large cortex layer consisting of 12-16 cell rows beneath the periderm. Secretory ducts formed by 5-12 secretory cells embedded in the cortex and located near vascular bundle were found at the root that is in early stage of secondary development. The stem was circular-pentagonal shaped in cross-section. There was lamellar collenchyma beneath epidermis of pentagon corners, and cortex parenchyma between corners. Secretory ducts located near the phloem, between the cortex and endodermis on the interfascicular region, were also observed. Endodermis layer was evident and its cells have indentations and protrusions where they touch adjacent endodermis cells, which strengthen the connection between them. In addition, casparian strips was conspicuous in many endodermis cells. Leaf midrib area was triangular shaped in cross section. There were secretory ducts, consisting of 4-5 secretory cells observed on both sides of the sclerenchymatous fibers which accompaning xylem. The leaf lamina was amphistomatic and stomata type was anomocytic. Mesophyll layer was equifacial. There was a large secretory duct and its diameter is bigger than the nearest main lamina vascular bundle. Achene shape was lanceolate-oblong and its surface was ribbed and glabrous of A. sivasica.

PENGARUH PUPUK KISERIT TERHADAP PERTUMBUHAN KELAPA SAWIT DAN PRODUKTIVITAS TANAH

<p>ABSTRAK</p><p>Perluasan lahan perkebunan kelapa sawit lebih diarahkan padalahan-lahan di luar Pulau Jawa. Lahan yang tersedia bersifat marginalseperti pada tanah Ultisols dan Oxisols. Pada lahan tanah tersebut telahmengalami pencucian yang hebat karena curah hujan yang tinggi sehinggakadar hara Mg rendah. Sumber hara Mg yang banyak digunakan adalahpupuk kiserit (Mg dan S), dolomit (Ca dan Mg) dan pupuk majemuk.Penelitian bertujuan untuk mempelajari peranan pupuk kiserit terhadappertumbuhan dan produktivitas tanah. Penelitian dilakukan di kebunpembibitan Cimulang, Kabupaten Bogor (PTP. Nusantara VIII), padaFebruari – Desember 2005. Tanah yang digunakan untuk penelitian adalahUltisols dan Oxisols. Rancangan menggunakan acak kelompok, 5perlakuan, ulangan 9 kali. Satu perlakuan terdiri dari satu tanaman bibitkelapa sawit. Pupuk Mg yang digunakan adalah kiserit powder 2 Pandadan kiserit yang telah beredar di pasaran sebagai standar. Dosis pupukkiserit yang dicoba: 0; 0,5; 1,0; dan 1,5 g/tanaman. Pupuk kiserit danpupuk dasar diberikan setiap 2 minggu sekali atau 12 kali pemberian.Pemupukan pertama diberikan pada umur 1 minggu, mulai pemupukan ke-2 dosis pupuk dikalikan 2, mulai minggu ke 10 dosis pupuk dikalikan 3,dan mulai minggu ke-18 dosis pupuk dikalikan 4. Contoh tanah bulk darilapang dikeringanginkan, diayak dengan saringan 2 mm, ditimbang 20 kgdan dimasukkan ke dalam polybag. Hasil penelitian menunjukkan bahwapemupukan kiserit pada Ultisols dapat meningkatkan tinggi, jumlah daun,diameter batang, bobot kering tanaman bibit kelapa sawit, serta mening-katkan hara Mg dalam tanah dari 1,25 menjadi 3,04 me/100 g dan kadarMg dalam tanaman menjadi 0,31 g/100 g. Pemupukan kiserit pada Oxisolsmeningkatkan tinggi, jumlah daun, diameter batang, bobot kering tanamanbibit kelapa sawit, serta meningkatkan hara Mg dalam tanah dari 0,28menjadi 2,36 me/100 g dan kadar Mg dalam tanaman menjadi 0,34 g/100g.Dosis optimum pupuk kiserit pada Ultisols dan Oxisols sama yaitu 0,80 g/tanaman. Pengaruh pupuk kiserit terhadap pertumbuhan bibit kelapa sawitdan produktivitas tanah sama dengan kiserit yang telah beredar di pasaransebagai standar.</p><p>Kata kunci: Elaeis guineensis, pupuk kiserit, status hara Mg, pertumbuhantanaman, produktivitas tanah</p><p>ABSTRACT</p><p>The Effect of Kieserite Fertilizer to Oil Palm Growth andSoil Productivity</p><p>The expansion of oil palm plantation is driven to outside JavaIsland. The available lands are marginal such as Ultisols and Oxisols,where intensive bleaching occurs for the high rate of rainfall, and causesthe low content of magnesium in such land. There are three sources used toprovide the Mg nutrient, such as kieserite (Mg and S), dolomite (Ca andMg) and compound fertilizer. The objective of this experiment was tostudy the effect of kieserite fertilizer on plant growth and soil productivity.This research was conducted in the seedling plot of Cimulang Site, BogorDistrict (PTP. Nusantara VIII) in February- December 2005 on Ultisolsand Oxisols using a randomized complete block design with 5 treatmentsand 9 replicates. One oil palm seedling was planted in each treatment. Thisexperiment used kieserite powder 2 Panda to provide Mg and ordinaryKieserite as the standard. The kieserite dosages were 0, 0.5, 1.0, and 1.5g/plant. Fertilizing the plot was done every 2 weeks, using kieserite andbasic fertilizer or fertilizing 12 times, but the first fertilization was donewhen the plants reached 1 week of age. Starting on the second fertilization,the dosage was multiplied 2 times, and starting on the 10 th week, thedosage was multiplied 3 times, and starting on 18 th week the dosage offertilizing is multiplied 4 times. Bulk soil samples were air-dried, sievedpassing 2 mm siever, and put 20 kg into polybags. The research resultshowed that kieserite fertilization on Ultisols increased plant height,number of leaves, stems (leaf midrib) diameter, dry weight of biomass, Mgnutrient content in the soil (from 1.25 to 3.04 me/100 g), and alsoincreased the plant Mg content to become 0.31 g/100 g. In addition,kieserite fertilization on Oxisols increased plant height, number of leaves,stems (leaf midrib) diameter, plant dry weight of oil palm seedling, Mgnutrient content in the soil, (from 0.28 into 2.38 me/100 g), and increasedplant Mg content into 0.34 g/100 g. The optimum kieserite fertilizingdosage on Ultisols and Oxisols was just the same, i.e. 0.80 g/plant. Theeffect of these two kinds of kieserite to the plant growth and soilproductivity was just almost the same.</p><p>Key words: Elaeis guineensis, kieserite fertilizer, Mg nutrient status, plantgrowth, soil productivity</p>

Effect of Activator on Levels of C, N, P and K Compost of Salak Sidimpuan Leaf Midrib

Salak Sidimpuan leaf midrib is abundant pruning waste. Salak Sidimpuan leaf midrib can becomposted containing a number of nutrients (carbon, Nitrogen, phosphorus, and potassium) for plantgrowth. To speed up the process of composting of salak leaf midrib can be done by giving a numberof activators. This study aims to see the effect of activator on the level of elements C, N, P and Kcompost of salak Sidimpuan leaf midribs. This study used a one-factor randomized block design with4 levels of treatment of activator, K0 = control, K1 = chopped midribs+cow manure fertilizer, K2 =chopped midribs+EM4, K3 = chopped midribs+cow manure fertilizer+EM4) with three replications.Data were analyzed with ANOVA and continued with DMRT test at 5% level if the F test showed areal effect. The results showed that the K2 with treatment chopped salak Sidimpuan leaf midrib andEM4 activator tended to give the best results in reducing the levels of C-organic and C/N ratio aswell as increasing total Nitrogen, total phosphorus and total potassium after composting comparedto other activator delivery treatments.

To furcate or not to furcate: the dance between vessel number and diameter in leaves

This article comments on:Lechthaler S, Colangeli P, Gazzabin M, Anfodillo T. 2019. Axial anatomy of the leaf midrib provides new insights into the hydraulic architecture and cavitation patterns of Acer pseudoplatanus leaves. Journal of Experimental Botany 70, 6195–6202.