Complete Genome Sequence of Dickeya dadantii subsp. dieffenbachiae Strain S3-1, Isolated from a White-Flowered Calla Lily in Taiwan

Erwinia chrysanthemi S3-1 is a bacterial soft rot pathogen of the white-flowered calla lily. The complete genome sequence of the strain was determined and used to reclassify the strain as Dickeya dadantii subsp. dieffenbachiae . The sequence will be useful to study plant host-driven speciation in strains of D. dadantii .

Mechanism Underlying Color Variation in Calla Lily Spathes Based on Transcriptomic Analysis

The calla lily (Zantedeschia hybrida) is a valued ornamental plant due to its unique shape and color variations. To determine the mechanisms responsible for color development in the calla lily spathe, we conducted a comparative transcriptomic analysis of the spathes of the black [Black Girl (B)], pink [Romantic (P)], and white [Ventura (W)] cultivars. The gene expression patterns in six spathe colors, including the preceding three colors as well as the amaranth [Promise (N)], red [Figo (F)], and yellow [Sun Club (Y)] cultivars were analyzed by real-time quantitative polymerase chain reaction (PCR). Transcriptomic analysis identified 25,165 differentially expressed genes. The transcription abundance and expression level of genes annotated as anthocyanidin reductase (ANR1, ANR2), basic-helix-loop-helix (bHLH1), and glutathione S-transferases (GST1) were significantly upregulated in B, and the expression of anthocyanidin synthase (ANS) was highest in B except for N. However, chalcone isomerase (CHI2) and dihydroflavonol 4-reductase (DFR1, DFR2) were expressed at significantly lower levels in P, W, and Y. Correlation analysis revealed that bHLH1 might act as a positive regulator of ANS expression, promoting anthocyanin synthesis. Moreover, GST1-encoded proteins may be related to the accumulation and transport of both anthocyanin and procyanidin in the calla lily spathe. It is speculated that the formation of the black spathe is related to the accumulation of anthocyanins and procyanidins. However, the low expression of CHI2, DFR1, and DFR2 may result in the inhibition of anthocyanin synthesis, which may lead to lightening of the spathe color. This preliminary study revealed the mechanism responsible for calla lily spathe color, identifying the key genes involved, thus providing effective gene resources and a theoretical basis for flower color molecular breeding.

Water relations in cut calla lily flowers maintained under different postharvest solutions

The use of chemicals in storage solutions has proved beneficial for the postharvest conservation of cut flowers. However, the effect of these solutions on the water relations of some species is still unknown. Therefore, the objective of the present investigation was to evaluate the water relations in calla lily flowers harvested at different stages and maintained under postharvest solutions with different chemicals. The flower stems were harvested in two stages of spathe opening: the early stage (cartridge) and the 1/3 flower opening stage. The flower stems were dipped in solutions with water (control), 100 mg L-1 sodium hypochlorite (NaClO), 100 mg L-1 aluminum sulfate [Al2(SO4)3], 200 mg L-1 8-hydroxyquinoline (8-HQ) and 10 mg L-1 silver nitrate (AgNO3). Over 9 days, the floral stems were kept in a room at 21 ± 2 °C and 75% ± 5% relative humidity and evaluated for changes in the pH of the solution and the water absorption, transpiration and commercial quality of the cut flowers. The addition of conservation substances to the storage solution induced spathe opening at both harvest stages and promoted water absorption by the stems, thus increasing the efficiency of flower hydration. The water balance maintenance was best for stems stored in water and storage solutions with Al2(SO4)3.

Yield and Quality of Inflorescences in the Zantedeschia albomaculata (Hook.) Baill. ‘Albomaculata’ after the Treatment with AMF and GA3

This study was conducted to assess the influence of gibberellic acid (GA3) and arbuscular mycorrhizal fungi (AMF) on the flowering and quality of Zantedeschia albomaculata (Hook.) Baill ‘Albomaculata’ plants. Before planting, the rhizomes were soaked in water or an aqueous solution of GA3 at a concentration of 150 mg dm−3 for 30 min. A mixture of AMF was applied to the rhizomes a week after planting. The AMF treatment increased the yield of inflorescences of the ‘Albomaculata’ cultivar by 100%. AMF and GA3 had a favourable effect on the quality of inflorescences, expressed by the length of peduncles, whereas AMF individually positively affected the length of the spathes. AMF and GA3 had no effect on the level of macroelements in calla lily leaves, with the exception of calcium (Ca). The leaves of mycorrhized plants had a high content of sodium (Na) and micronutrients, except for iron (Fe). The results of the study showed that GA3 could be replaced by mycorrhizal inoculation when applied to Zantedeschia plants.

Host Specificity and Differential Pathogenicity of Pectobacterium Strains from Dicot and Monocot Hosts

Recent phylogenetic studies have transferred certain isolates from monocot plants previously included in the heterogeneous group of Pectobacteriumcarotovorum (Pc) to a species level termed Pectobacterium aroidearum. The specificity of Pectobacterium associated infections had received less attention, and may be of high scientific and economic importance. Here, we have characterized differential responses of Pectobacterium isolates from potato (WPP14) and calla lily (PC16) on two typical hosts: Brassica oleracea var. capitata (cabbage) a dicot host; and Zantedeschia aethiopica (calla lily) a monocot host. The results revealed clear host specific responses following infection with the two bacterial strains. This was demonstrated by differential production of volatile organic compounds (VOCs) and the expression of plant defense-related genes (pal, PR-1, lox2, ast). A related pattern was observed in bacterial responses to each of the host’s extract, with differential expression of virulence-related determinants and genes associated with quorum-sensing and plant cell wall-degrading enzymes. The differences were associated with each strain’s competence on its respective host.

Desenvolvimento e potencial fitorremediador de espécies florícolas em resposta ao excesso de cobre no solo

A contaminação de Cu (cobre) no solo é um problema recorrente, sobretudo em áreas vitivinícolas e, na tentativa de amenizar os efeitos nocivos desse elemento no solo, a utilização da técnica de fitorremediação tem apresentado resultados positivos. Assim, o objetivo deste trabalho foi avaliar o desenvolvimento vegetativo e o potencial fitorremediador utilizando diferentes espécies de flores (calla-lily, cravina-de-jardim e crisântemo) em resposta ao excesso de Cu no solo, buscando uma agricultura de baixo impacto ambiental. O experimento foi realizado em delineamento inteiramente casualizado, em esquema 3x4 (flores: calla-lily, cravina-de-jardim e crisântemo e doses de Cu no solo: zero (sem adição), 250, 500 e 750 mg kg-1), com cinco repetições, em casa de vegetação. O solo utilizado foi coletado em área vitivinícola do município de Pinto Bandeira (RS), com 75 anos de cultivo, apresentando alto teor de Cu no solo. Observou-se que as três espécies florícolas apresentam tolerância ao cultivo em solo com excesso de Cu, contudo, verificou-se que o incremento de Cu no solo afetou negativamente o desenvolvimento típico das espécies de calla-lily e crisântemo, inclusive no florescimento. E, que nas mesmas condições, a cravina-de-jardim demonstrou-se com boas aptidões fitorremediativas, com exuberante florescimento e sem indícios de fitotoxidez, sendo esta promissora à fitorremediação do solo.