Far-Red Light-Induced Azolla filiculoides Symbiosis Sexual Reproduction: Responsive Transcripts of Symbiont Nostoc azollae Encode Transporters Whilst Those of the Fern Relate to the Angiosperm Floral Transition

Water ferns of the genus Azolla and the filamentous cyanobacteria Nostoc azollae constitute a model symbiosis that enabled the colonization of the water surface with traits highly desirable for the development of more sustainable crops: their floating mats capture CO2 and fix N2 at high rates using light energy. Their mode of sexual reproduction is heterosporous. The regulation of the transition from the vegetative phase to the spore forming phase in ferns is largely unknown, yet a prerequisite for Azolla domestication, and of particular interest as ferns represent the sister lineage of seed plants. Sporocarps induced with far red light could be crossed so as to verify species attribution of strains from the Netherlands but not of the strain from the Anzali lagoon in Iran; the latter strain was assigned to a novel species cluster from South America. Red-dominated light suppresses the formation of dissemination stages in both gametophyte- and sporophyte-dominated lineages of plants, the response likely is a convergent ecological strategy to open fields. FR-responsive transcripts included those from MIKCC homologues of CMADS1 and miR319-controlled GAMYB transcription factors in the fern, transporters in N. azollae, and ycf2 in chloroplasts. Loci of conserved microRNA (miRNA) in the fern lineage included miR172, yet FR only induced miR529 and miR535, and reduced miR319 and miR159. Phylogenomic analyses of MIKCC TFs suggested that the control of flowering and flower organ specification may have originated from the diploid to haploid phase transition in the homosporous common ancestor of ferns and seed plants.

Identifikasi Tumbuhan Paku Air (Azolla sp.) Secara Morfologi dan Molekuler dengan Menggunakan Gen rbcL (Identification of Water Ferns (Azolla sp.) Based on Morphologycal Traits and Molecular Marker Using rbcL Gene)

Abstrak Azolla merupakan salah satu tumbuhan paku air yang memiliki banyak manfaat, namun belum banyak dikenal dan sering dianggap sebagai tumbuhan gulma. Pengidentifikasian akan keberadaan jenis-jenis tumbuhan paku air (Azolla sp.) penting untuk dilakukan guna mendukung upaya pengembangan, pembudidayaan dan eksplorasi tumbuhan Azolla sp. Penelitian ini bertujuan untuk mengidentifikasi spesies tumbuhan paku air (Azolla sp.) secara morfologi dan molekuler dengan menggunakan gen rbcL. Hasil penelitian menunjukkan bahwa berdasarkan karakter morfologi sampel tumbuhan Azolla sp. asal Tondano Sulawesi Utara menunjukkan kemiripan dengan spesies A. pinnata dan Azolla asal Magelang Jawa Tengah menunjukkan kemiripan dengan spesies A. microphylla. Identifikasi menggunakan sekuens gen rbcL menunjukkan bahwa sekuens sampel tumbuhan Azolla asal Tondano (WM1) memiliki tingkat kemiripan 100% dengan A. pinnata dan Azolla asal Magelang (WM2) memiliki tingkat kemiripan 100% dengan A. microphylla yang terdapat dalam GenBank. Analisis jarak genetik menunjukkan kedua sampel WM1 dan WM2 memiliki hubungan kekerabatan yang cukup dekat dengan nilai jarak genetik 0,060.Kata kunci: Azolla sp., identifikasi morfologi, identifikasi molekuler, gen rbcL Abstract Azolla is one of the water ferns that has many benefits, but it is not yet widely known and is often regarded as a weed plant. Identification of water ferns (Azolla sp.) is important to be carried out to support the development, cultivation, and exploration of Azolla sp. This study aimed to identify species of aquatic plants (Azolla sp.) morphologically and molecularly using the gene rbcL. The results demonstrated that based on the morphological characters, the Azolla sp. from Tondano, North Sulawesi, showed similarity with species A. pinnata and Azolla from Magelang, Central Java, showed similarity to species A. microphylla. Identification using rbcL gene sequences showed that the sample sequence of plants Azolla from Tondano (WM1) had a 100% similarity level with A. pinnata and Azolla from Magelang (WM2) had a 100% similarity level with A. microphylla available in GenBank. Genetic distance analysis showed that both WM1 and WM2 samples had a close relationship with the genetic distance value of 0.060.Key words: Azolla sp., morphological identification, molecular identification, rbcL gene