การตอบสนองทางสรีรวิทยาและการแสดงออกของยีน PsbS1 ที่ตอบสนองต่อภาวะเครียดจากความเค็มของข้าวสายพันธุ์ทนเค็มที่ได้จากประชากร CSSL / พนิตา ชุติมานุกูล = Physiological responses and PsbS1 gene expression responding to salt stress condition of salt-tolerant rice lines obtained from CSSL population / Panita Chutimanukul
This research was aimed to evaluate some physiological responses of the chromosome segment substitution lines (CSSL), containing various regions between RM1003 and RM3362 markers on chromosome 1 of rice. These CSSLs had ‘KDML105’ rice genetic background and obtained the putative salt tolerant regions from the chromosome 1 of the drought tolerant double haploid line, DH212. Therefore, the experiments were performed to evaluate salt-stress responses among CSSLs, ‘KDML105’ and DH212 rice, in comparison with the salt tolerant standard cultivar, ‘Pokkali’ rice and salt susceptible cultivar, ‘IR29’ rice. To determine the appropriate period for physiological response study, it was found that after 21 days under 150 mM NaCI treatment, ‘KDML105’ and ‘IR29’ rice could not prolong life in this condition. Therefore, the evaluation experiments on CSSLs were performed up to 18 days after treatments. and the data were collected on 0, 6, 12 and 18 days after treatments. After 18 days of 75 mM NaCI treatment, CSSL16 showed the best growth responses among the tested plant lines, while the growth performance of CSSL10 was the best under 150 mM NaCI treatment. Both of them possessed the full segment between RM1003 and RM3362 markers of chromosome 1. The maximum photosynthetic rate (Amax) on day 18 after 75 mM NaCI treatment of all CSSLs containing the full segment of putative tolerant region from chromosome1, CSSL10, CSSL12, and CSSL26, which contained only some part of the putative tolerant region, between RM3462 and RM529. Interestingly, CSSL27, containing the putative tolerant region, between RM7594 and RM3442 also showed the increase in Amax. One of the important genes involving in photosynthesis is PsbS1gene, encoding chlorophyll a/b binding protein, which is the component in photosystem II complex. CSSL27 and CSSLs, containing the full segments of the putative tolerant region obtained PsbS1gene from DH212 rice, while CSSL26 obtained this gene from ‘KDML105’rice. The PsbS1gene expression during 75 mM NaCI treatment was compared among CSSL11, CSSL16, CSSL26, CSSL27, ‘KDML105’ and DH212. The significant reduction in PsbS1gene expression during 18 days of salt stress was found in ‘KDML105’ and CSSL26, while other CSSLs tested showed the ability to adapt the level of PsbS1gene expression similar to what was found in DH212. These data suggested the difference in the regulation of PsbS1gene expression during salt stress in these plant lines, which contributed to the adaptation in photosynthesis process during salt stress and lead to salt tolerant ability in rice.
