Effects of Phosphate Starvation Responses Gene OsSQD2.1 on Growth in Rice

doi:10.16819/j.1001-7216.2020.9074

Abstract

Abstract:

【Objective】This work aims at confirming the effects of gene OsSQD2.1, involved in phosphate starvation responses on rice growth so as to reveal its function. 【Method】The bioinformatics method was used to determine the OsSQD2.1 gene and its protein structure and the cis-acting elements on the OsSQD2.1 promoter. The expression of OsSQD2.1 under different deficiency conditions was measured by real-time PCR. For an insight into the effects of OsSQD2.1 on the growth and photosynthesis of transgenic plants, we determined the phenotype, phosphorus content and net photosynthetic rate of DNA insertion mutants and silencing interfering materials at different growth stages. 【Result】The coding region of the OsSQD2.1 gene is 3548 bp in length and it is located on chromosome 1, with 11 exons and 10 introns. OsSQD2.1 belongs to the glycosyltransferase family; OsSQD2.1 promoter contains multiple reported cis-acting elements responsive to phosphorus deficiency; OsSQD2.1 was induced by phosphorus deficiency and inhibited by sulfur deficiency. Compared with the wild type, the shoot length and primary root length during the vegetative growth period in the mutant or silencing materials were significantly lower than the wild type. During the reproductive growth, the plant height as well as 1000-grain weight of the mutant or silencing material was significantly lower than that of wild type, and there was no significant difference in seed setting rate; The total phosphorus contents in the leaves were not significantly different in the wild type under the phosphorus deficiency condition. In addition, the net photosynthetic rate of the seedling and mature mutants was significantly lower than that of the wild type, and it was presumed that OsSQD2.1 affected the net photosynthetic rate of rice. 【Conclusion】The results confirm that OsSQD2.1 is phosphorus deficiency-responsive and affects rice growth.

Key words: phosphate, phosphate starvation response, phosphorus deficiency, rice, development

摘要：

【目的】旨在研究水稻缺磷响应基因OsSQD2.1对水稻生长发育的影响,从而解析其作用。【方法】通过生物信息学的方法,确定OsSQD2.1基因及蛋白结构并分析OsSQD2.1启动子上的顺式作用元件;通过荧光定量PCR检测,研究不同缺素条件下OsSQD2.1的表达;测定T-DNA插入突变体和沉默干涉材料不同时期表型、磷含量和净光合速率,研究OsSQD2.1对转基因植株生长发育及光合作用的影响。【结果】OsSQD2.1基因编码区全长为3548 bp,位于第1染色体上,具有11个外显子和10个内含子,OsSQD2.1属于糖基转移酶家族;OsSQD2.1启动子上含有多个缺磷响应顺式作用元件;OsSQD2.1受缺磷诱导,缺硫抑制。营养生长期突变体或沉默材料地上部长度和主根长均显著低于野生型。生殖生长期,突变体或沉默材料株高和千粒重显著低于野生型,结实率无显著差异。OsSQD2.1的突变与沉默增加正常供磷时叶片中的总磷,在缺磷条件时野生型相比无明显差异;此外,苗期和成熟期突变体的净光合速率显著低于野生型,初步推测OsSQD2.1影响水稻净光合速率。【结论】OsSQD2.1受缺磷响应,并影响水稻生长发育。

关键词: 磷, 缺磷响应, 缺磷, 水稻, 生长发育

CLC Number:

Q755
Q945.1

Lu LIU, Chuanshan XU, Yafei SUN, Zhi HU, Hao AI, Xiuli LIU, Xiaowen WANG, Shubin SUN. Effects of Phosphate Starvation Responses Gene OsSQD2.1 on Growth in Rice[J]. Chinese Journal OF Rice Science, 2020, 34(3): 237-244.

刘璐, 许传山, 孙雅菲, 胡志, 艾昊, 刘秀丽, 王小文, 孙淑斌. 缺磷响应基因OsSQD2.1对水稻生长发育的影响[J]. 中国水稻科学, 2020, 34(3): 237-244.

Figures/Tables 9

Table 1 Primers used to amplify the Actin and OsSQD2.1 cDNA for quantitative Q-PCR.

基因名称 Gene name	引物序列(5′-3′) Primer sequence	退火温度 Annealing temperature /℃
OsSQD2.1	F: CGAAGACAATACGCAATGA	55
OsSQD2.1	R: CGGTGAACGATTCCTGAA	55
OsActin	F: GGGCCCACGCTTTGTTG	57
OsActin	R: AGCACGGCTTGAATAGCG	57

Fig. 1. Comparison of genes and domain structures of SQD2 in rice and Arabidopsis. A, Location and length of the introns and exons of AtSQD2, OsSQD2.1, OsSQD2.2 and OsSQD2.3. The white and black boxes and black lines represent UTRs, exons and introns, respectively. B, GT-like-binding domain in AtSQD2 and OsSQD2 family are represented with black boxes and the numbers at the top of the box indicate the location of these domains.

Fig. 2. Motif analysis of the identified promoters of OsSQD2.1.

Fig. 3. Relative expression of OsSQD2.1 in response to phosphorus deficiency(-P) and sulfur deficiency(-S). Different letters indicate significant difference at 0.05 level. The same as below.

Fig. 4. Identification of homozygous T-DNA insertion mutants of OsSQD2.1. A, Information of T-DNA insertion in OsSQD2.1 genes; B and C, Homozygous mutants identification by two-rounds PCR (B) and gene silence effects (C) of ossqd2.1 by RT-PCR.

Fig. 5. Phenotype of OsSQD2.1 mutation and silencing(Ri1 and Ri1) at seedling stage(Mean±SE, n=5).

Fig. 6. Total P concentration in leaves of pot-cultured wild type, ossqd2.1 and OsSQD2.1-RNAi materials(Ri1 and Ri1) under Pi-sufficient and Pi-deficiency conditions(Mean±SE, n=5).

Fig. 7. Phenotype of WT, ossqd2.1 and OsSQD2.1-RNAi lines(Ri1 and Ri1) at maturity stage(Mean±SE, n=5).

Fig. 8. Net photosynthetic rate of WT, ossqd2.1 and OsSQD2.1-RNAi lines(Ri1 and Ri1) at the seedling stage(A) and the maturity stage(B) (Mean±SE, n=5).

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