Identification of miRNAs responsive to K+deficiency stress
From the 10 differentially expressed mature miRNAs, seven known miRNAs
were chosen to detect their expression under K+deficiency stress by RT-PCR (Fig. 7). In the low K+sensitive genotype tomato ‘JZ18’, the expression levels ofstu-miR08006 and stu-miR-8007b were decreased after low
K+ treatment for 12 h. Ppe-miR858 ,stu-miR-384 , ath-miR-171a , stu-miR-8039 , andstu-miR-530 expression levels were all upregulated after low
K+ treatment for 3 days in JZ18 tomatoes. In the low
K+ tolerant genotype tomato ‘JZ34’,stu-miR-8006 expression was significantly increased after low
K+ treatment for 3 and 5 days, whereasstu-miR-8007b expression was increased after low
K+ treatment for 12 h and 3 days. In contrast,ppe-miR-858 , stu-miR-384 , ath-miR-171a ,stu-miR-8039 , and stu-miR-530 expression levels tended to
decrease following low K+ treatment in JZ34. Taken
together, these findings suggested that stu-miR-8006 andstu-miR-8007 positively responded to K+deficiency stress in low K+ tolerant tomatoes, whereasppe-miR-858 , stu-miR-384 , ath-miR-171a ,stu-miR-8039 , and stu-miR-530 negatively responded to
K+ deficiency stress in low K+tolerant tomatoes.