Characterization of a Novel Rice Dynamic Narrow-Rolled Leaf Mutant with Deficiencies in Aromatic Amino Acids

The leaf blade is the main photosynthetic organ and its morphology is related to light energy capture and conversion efficiency. We isolated a novel rice Dynamic Narrow-Rolled Leaf 1 (dnrl1) mutant showing reduced width of leaf blades, rolled leaves and lower chlorophyll content. The narrow-rolled leaf phenotype resulted from the reduced number of small longitudinal veins per leaf, smaller size and irregular arrangement of bulliform cells compared with the wild-type. DNRL1 was mapped to chromosome 7 and encoded a putative 3-deoxy-7-phosphoheptulonate synthase (DAHPS) which catalyzes the conversion of phosphoenolpyruvate and D-erythrose 4-phosphate to DAHP and phosphate. Sequence analysis revealed that a single base substitution (T–A) was detected in dnrl1, leading to a single amino acid change (L376H) in the coding protein. The mutation led to a lower expression level of DNRL1 as well as the lower activity of DAHPS in the mutant compared with the wild type. Genetic complementation and over-expression of DNRL1 could rescue the narrow-rolled phenotype. DNRL1 was constitutively expressed in all tested organs and exhibited different expression patterns from other narrow-rolled leaf genes. DNRL1-GFP located to chloroplasts. The lower level of chlorophyll in dnrl1 was associated with the downregulation of the genes responsible for chlorophyll biosynthesis and photosynthesis. Furthermore, dnrl1 showed significantly reduced levels of aromatic amino acids including Trp, Phe and Tyr. We conclude that OsDAHPS, encoded by DNRL1, plays a critical role in leaf morphogenesis by mediating the biosynthesis of amino acids in rice.

EFFECT OF CITRONELLA NANO BIOPESTICIDE AGAINST MOSAIC VIRUS AND ITS VECTOR ON PATCHOULI

<p>The mosaic disease declines production and oil quality of patchouli. Antiviral-based citronella oil has been formulated using a spontaneous emulsification technique (nanotechnology). The previous result of the greenhouse trial showed the formula at 1-1.5 % concentrations suppressed the development of virus of about 82.5 %. The field-scale tests is necessary to be performed to validate the effectiveness of citronella nano biopesticide (CNB) against the mosaic virus and its vector on patchouli. The study was conducted in patchouli plantation at two locations (Pandeglang, Banten and Manoko, West Java). The research was arranged in a Randomized Completed Block Design (RCBD) with 6 treatments and 10 replications, each replication consisted of 50 plants. The treatments were formula of CNB at the concentration of (1) 0.5 %, (2) 1 %, (3) 1.5 %, (4) 2 %, (5) insecticide (deltamethrin 0.2 %), and (6) control. The results showed that CNB formula at 1 % concentration with a monthly application effectively suppressed the development of mosaic disease in patchouli plants, and at 2 % concentration to control rolled-leaf aphid. The lowest intensity of mosaic disease (at 1 % concentration) was in Banten (23.12 %) and in West Java (18.35 %), while in control ranged from 26.31-44.94 % (Banten) and 19.60-23.12 % (West Java). Efficacy Index (EI) in Banten ranged from 12.12-48.55 % and in West Java was 6.38-20.63 %. The lowest intensity of aphid attack was showed by insecticide and CNB at 2 % concentration. The EI of CNB was 35.33 % (Banten) and 51.71 % (West Java<strong>) </strong>respectively.</p>

CRISPR/Cas9-Induced Mutagenesis of Semi-Rolled Leaf1,2 Confers Curled Leaf Phenotype and Drought Tolerance by Influencing Protein Expression Patterns and ROS Scavenging in Rice (Oryza sativa L.)

Rice leaf morphology is an essential agronomic trait to develop drought-tolerant genotypes for adequate and stable crop production in drought-prone areas. Here, rolled leaf mutant plants were acquired by CRISPR/Cas9-based mutagenesis of Semi-rolled leaf1,2 (SRL1 and SRL2) genes, and isobaric tags for relative and absolute quantification (iTRAQ) based proteomic analysis was performed to analyze the subsequent proteomic regulation events. Homozygous mutants exhibit decreased chlorophyll content, transpiration rate, stomatal conductance, vascular bundles (VB), stomatal number, and agronomic traits with increased panicle number and bulliform cells (BCs). Under drought stress, mutant plants displayed lower malondialdehyde (MDA) content while higher survival rate, abscisic acid (ABA) content, superoxide dismutase (SOD), catalase (CAT) activities, and grain filling percentage compare with their wild type (WT). Proteomic results revealed that 270 proteins were significantly downregulated, and 107 proteins were upregulated in the mutant line compared with WT. Proteins related to lateral organ boundaries’ (LOB) domain (LBD) were downregulated, whereas abiotic stress-responsive proteins were upregulated in the CRISPR mutant. LBD proteins (Q5KQR7, Q6K713, Q7XGL4, Q8LQH4), probable indole-3-acetic acid-amido synthetase (Q60EJ6), putative auxin transporter-like protein 4 (Q53JG7), Monoculm 1 (Q84MM9) and AP2 (Apetala2) domain-containing protein (Q10A97) were found to be hub-proteins. The hybrids developed from mutant restorers showed a semi-rolled leaf phenotype with increased panicle number, grain number per panicle, and yield per plant. Our findings reveal the intrinsic value of genome editing and expand the knowledge about the network of proteins for leaf rolling and drought avoidance in rice.

A new species of gall midge (Diptera: Cecidomyiidae) attacking jujube, Ziziphus jujuba in China

Dasineura jujubifolia Jiao & Bu, sp. nov., a gall midge feeding on jujube, Ziziphus jujuba Miller (Rhamnaceae), a fruit tree cultivated extensively in large areas of China, is described and illustrated based on specimens collected from Alar (Xinjiang, China). The new gall midge species causes rolled leaf galls on Ziziphus jujuba in Northwestern China. Brief notes on the biology of the jujube gall midge are given.