Proline assay kit

Cotton leaf tissues were sampled, and the activities of three enzymes were measured after drought treatment. Enzyme activities of the control plants were also measured from seedlings grown in normal conditions (CK). Proline, superoxide dismutase (SOD), micro malondialdehyde (MDA), and catalase (CAT) activities were measured using the Solarbio Proline Assay Kit BC0290; Superoxide Dismutase Assay Kit: BC0170; Micro Catalase Assay Kit: BC0205; and Micro Malondialdehyde (MDA) Assay Kit: BC0025, Beijing, China), respectively.

The genetic standard TM-1 cultivar was chosen for VIGS assays in this study. A 300bp fragment of GhPP2-33 (291–590bp) was cloned into the pTRV2(pYL156) vector. The vectors pTRV2: 00, pTRV2:GhPP2-33, pTRV2: PDS, pTRV1 (pYL192, helper vector) were transformed into A.tumefaciens strain LBA4404. The experiments of the culture of A.tumefaciens and injection are the same as our previous studies [50 , 52 (link)]. When the pTRV2: PDS plants showed an albino phenotype, the silencing efficiency of the pTRV2: GhPP2-33 and pTRV2: 00 plants were further determined by qRT-PCR experiments. Next, the pTRV2: GhPP2-33 and pTRV2: 00 plants were treated with 400mM salt for two days. The contents of MDA and Proline were determined using Malondialdehyde (MDA) Assay Kit and Proline Assay Kit according to the standard methods (Solarbio, Beijing, China), respectively.

Proline was determined using a validated proline assay kit (Solarbio), with all samples being extracted according to the manufacturer’s protocol. Briefly, cells were lysed by sonication while tumor tissues were lysed using a grinder. Supernatants were shaken and extracted in boiling water for 10 min. After centrifugation for 10 min, room temperature, 1000 × g, supernatants were collected. Absorbance at 520 nm was used to determine proline level. Commercial detection kit used for proline assay are given in Supplementary Table 3.