[Gene expression of the key enzymes controlling starch synthesis and metabolism in rice grain endosperm under effects of high temperature after anthesis].
Taking an early-season indica cultivar 'Jiazao 935' whose grain quality was sensitive to temperature as test material, and by using artificial climatic chamber and real-time fluorescence quantitative PCR (FQ-PCR), this paper studied the relative expression amount and its dynamic changes of ten isoform genes of the key enzymes controlling starch synthesis and metabolism in rice grain endosperm, including sbe1, sbe3, and sbe4 of starch branching enzyme (SBE), isal, isa2, isa3, and pul of starch debranching enzyme (DBE), and Wx, sss1, and sss2a of starch synthase (SS), at the mean daily temperature 22 and 32 degrees C after anthesis. There existed obvious differences in the expression patterns of these genes under the high temperature stress, and the expression patterns were isoform-dependent. The relative expression amount of sbe1 and sbe3 under high temperature decreased significantly, and both of the genes were the sensitive isoform genes of SBE to high temperature stress. Among the DBE genes, pul was the isoform gene with high expression level, being more sensitive to high temperature stress than isa1, isa2, and isa3. Among the SS genes, sss2a had a significantly lower relative expression amount than sss1 and Wx, but sss2a and sss1 were more sensitive to high temperature than Wx, suggesting that sss2a and sss1 could be the important genes that adjusted the starch structure in rice endosperm under high temperature stress, especially at the middle and late grain filling stages.
School of Life Sciences, Wenzhou Medical College, Wenzhou 325035, Zhejiang, China. zhonglianjin@126.com
Lian-Jin
LJ
Zhong
Hu
H
Dong
Xiao-Bo
XB
Cai
Yan-Ning
YN
Feng
Ping
P
Ren
Fang-Min
FM
Cheng
D015061:1,4-alpha-Glucan Branching Enzyme / Q000235:genetics*; D002523:Edible Grain / Q000378:metabolism; D056625:Endosperm / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D006358:Hot Temperature; D012275:Oryza / Q000201:enzymology / Q000235:genetics*; D020033:Protein Isoforms / Q000235:genetics; D013213:Starch / Q000096:biosynthesis* / Q000378:metabolism; D013312:Stress, Physiological / Q000502:physiology
D020033:Protein Isoforms; D013213:Starch; D015061:1,4-alpha-Glucan Branching Enzyme