Transcriptome analysis of celery under limited calcium supply

Transcriptome of celery (Apium graveolens L.) under limited calcium (Ca) supply was analyzed by RNA sequencing, with the aim of understanding the impacts of Ca deficiency on plant metabolism. Plants without boron (B) supply were also included in the analysis, to compare the effects of deficiencies of Ca and B. Seeds of celery (cv. Cornell) were germinated on vermiculite in a culture room maintained at 25 degree C and 16/8 h light/dark cycle. Five weeks after germination, seedlings were transferred to a solution culture. The complete nutrient solution contained 1 mM Ca(NO3)2, 1 mM KCl, 0.5 mM MgSO4, 0.25 mM (NH4)2HPO4, 100 µM Fe(III)EDTA, 46 µM B(OH)3, 9 µM MnCl2, 0.8 µM ZnSO4, 0.3 µM CuSO4, and 0.1 µM (NH4)2Mo7O24. Two-month-old plants were then transferred to either -Ca, -B, or control medium. For -Ca treatment, Ca(NO3)2 was omitted from the solution and NO3- was supplemented as KNO3. For -B treatment, B(OH)3 was omitted from the solution. The uppermost leaves were sampled at 4 and 7 day after starting the treatment. Total RNA was extracted using an RNA extraction kit (RBC Bioscience).