Dur3 and nrt2 genes in the bloom-forming dinoflagellate Prorocentrum minimum: Transcriptional responses to available nitrogen sources

Bloom-forming potentially toxic dinoflagellates Prorocentrum cordatum in marine plankton food webs

“…Thus, dur3 expression levels were downregulated after the supplementation of additional N sources and were 1.7 to 2.6-fold lower than in the nitrate-grown culture, and the nrt2 expression levels decreased 1.9-fold in the presence of NH 4 + . Although the addition of N compounds did not affect the DNA synthesis rates of these protists, the transcription levels increased up to 12.5-fold after the N supplementation in the urea-limited treatments (Pechkovskaya et al, 2020).…”

“…Among the diversity of nitrogen sources and the variety of uptake mechanisms employed by P. cordatum are the negative response to NO 3 − in the presence of other nitrogen sources; strong affinity for NH 4 + and amino acids; affinity for urea not affected by temperature; and contribution of all of those substances as the primary nitrogen (N) sources; all those are supposed to aid the development and maintenance of blooms (Fan et al, 2003;Matantseva et al, 2016Matantseva et al, , 2018. Additionally, the evaluation of expression levels of urea transporter gene dur3 and nitrate transporter gene nrt2 in P. cordatum by RT-qPCR revealed their variable sensitivity to input of different N sources (Pechkovskaya et al, 2017(Pechkovskaya et al, , 2020. Thus, dur3 expression levels were downregulated after the supplementation of additional N sources and were 1.7 to 2.6-fold lower than in the nitrate-grown culture, and the nrt2 expression levels decreased 1.9-fold in the presence of NH 4 + .…”

“…Future investigations will provide the solutions of such topical questions as how the systems responsible for the nutrient uptake are distributed in the amphiesmal membranes, and do the morphological features like the flagellar canal and the pusule represent the major regions of the uptake and engulfment of various nutrient sources by dinoflagellates (Kalinina et al, 2018). Meanwhile, the ability of conquering the new environment by the invader, as was the case of the recent invasion of P. cordatum into the Baltic Sea, where it step-by-step suppressed, driven out and replaced the native con-generic species Prorocentrum balticum (Telesh et al, 2016), means not only adaptation to physical conditions and competitiveness with native species for nutrients on the basis of flexible metabolism of different nitrogen sources (Matantseva et al, 2016) and changes in photosynthesis on molecular level of transport genes (Pechkovskaya et al, 2017(Pechkovskaya et al, , 2020. It also implies the competitiveness as a prey and a predator, which means "to eat more and not being eaten up".…”

“…Specifically, until the late 1990-s there existed two similar species: Prorocentrum cordatum (Osten-feld) Dodge (or Exuviaella cordata Ostenfeld, 1901; originally identified in the samples from the Caspian Sea collected in 1898-1899, and later registered in the Aral, Azov and Black seas; Velikova and Larsen, 1999), and Prorocentrum minimum (Pavillard) Schiller (or Exuviaella minima Pavillard, 1916; originally described from the Gulf of Lion, the Mediterranean Sea;Pavillard, 1916). These two species differed morphologically only by the apparent complete absence of an apical spine in P. cordatum when examined by light microscopy.…”

Insights into Alexandrium minutum Nutrient Acquisition, Metabolism and Saxitoxin Biosynthesis through Comprehensive Transcriptome Survey

“…These results are in agreement with several previous studies proving that dinoflagellates of the genus Alexandrium are indeed capable of taking up nitrogen from this source into cells [ 64 , 65 ]. Several recent studies have shown that genes encoding nitrate transporting proteins in Prorocentrum donghaiense and Prorocentrum minimum were regulated at the transcriptional level and regulated with the changes of nitrogen in the environment [ 66 , 67 ]. Nevertheless, a study by Bellefeuille and Morse [ 68 ] found that nitrate transporting proteins in Lingulodinium polyedrum were continuously expressed with the presence of nitrogen.…”