Study Of Reasons For Hormones’ Changes Of Kernel Shrivel Variants In Peanut (Arachis Hypogaea L.)

Peanut(Arachis hypogaea L.) is a kind of important oil crops, economic crops and export crops. Peanut kernel’s plumpness is directly related to its production and quality,plant hormones play an important role in the process of growth and development of peanut kernel. In this study, we chose 05D610 whose pods and kernels grow normally, and 05D677 which is 05D610’s kernel shrivel variant strains. Under the same growing conditions, we measured the content of endogenous hormones(GA, ABA, ZT and IAA) in different tissues of two strains; we analyzed the difference of genes’ expression which is related to the synthesis of hormones in gene expression profiles; early inflation stage of pods, after dropping exogenous GA and ABA to young pods, we measured the content of endogenous hormone in young pods or kernels and the changes of dry matter accumulation. Throw those analysis, we study the reasons for hormones’ changes of kernel Shrivel Variants. The main findings are as follows:1.The analysis of GA content in different tissues of 05D677 and 05D610Early stage of podding, the content of GA was significantly different between05D677’s different tissues, the order from large to small: rolled leaves, pod needles,unrolled leaves, stem tips, pods, stems, the content of GA in rolled leaves was significantly higher than other tissues;the content of GA was significantly different between 05D610’s different tissues, the order from large to small: rolled leaves, pods, unrolled leaves, stem tips,pod needles, stems, the content of GA in rolled leaves was significantly higher than other tissues;05D677’s content of GA was significantly higher than 05D610 in rolled leaves, was significantly lower than 05D610 in other tissues.Late stage of podding, 05D677 or 05D610’s content of GA in rulled leaves, unrolled leaves and stem tips was significantly higher than other measured tissues(stems, fruit needle and fruit), among other tissues, the content of GA was different significantly, the order from large to small: pod needles, stem, pods. 05D677’s content of GA was lower than05D610 in rolled leaves, unrolled leaves and stem tips, significantly higher than 05D610 in pods, same to 05D610 in stem and pod needles.Harvest time, 05D677 or 05D610’s content of GA in unrulled leaves or stem tips wassignificantly higher than stem and pods, the content of GA did’t have difference between stem and pods.05D677’s content of GA was significantly higher than 05D610’s in all measured tissues.2. The analysis of ABA content in different tissues of 05D677 and 05D610Early stage of podding, the stem tips’ content of ABA was significantly higher than other measured tissues, and other tissues’ were not significantly different in 05D677. Stem tips and pods’ content of ABA was significantly higher than other tissues, and other tissues’ were not significantly different in 05D610. 05D677’s content of ABA in stem tips and pods was significantly lower than 05D610’s, same to 05D610 in other tissues.Late stage of podding, stem tips and stems’ content of ABA were significantly higher than other measured tissues, and other tissues’ were not significantly different in05D677.Stem tips’ content of ABA was significantly higher than other tissues’, and other tissues’ were not significantly different in 05D610.05D677’s content of ABA in stem tips was significantly lower than 05D610’s, significantly lower than 05D610’s in pods, same to05D610 in other tissues.Harvest time, stem tips’ content of ABA was significantly higher than unrolled leaves,stems and pods in 05D677. Pod needles and pods’ contents of ABA were significantly higher than unrolled leaves or stems’ in 05D610. 05D677’s content of ABA in pods was significantly lower than 05D610, same to 05D610 in other tissues.3. The expression’s difference of genes related to hormones’ synthesis in young podsThrow the cluster analysis of gene expression profiles, compared with 05D610, there seven key genes were down-regulated in 05D677: the rate-limiting enzyme DXS gene in MEP pathway, the rate-limiting enzyme CPS and KAO gene in GAs bio-synthesis, the rate-limiting enzyme IPT gene in ZT bio-synthesis, the early stage of the ABA synthesis carotenoids synthase gene, the rate-limiting enzyme ABA2 gene in ABA synthesis, the key enzyme tryptophan synthetase gene in tryptophan bio-synthesis; there four genes were up-regulated in 05D677: GA20 ox gene in GAs synthesis, trans-corn glucose nitrogen-based chemical enzyme genes, the rate-limiting enzyme 3-dehydroquinate quinoline dehydration gene and 3-dehydrogenation shikimate dehydrogenase gene in shikimate pathway. The reduce of genes’ expression may be related to the reduce of endogenous hormones in05D677’s young pods.4. Effects of exogenous GA treatment on endogenous hormone and dry matter accumulation in pods or kernelsExogenous GA treatment on young pods, throw significantly improving 05D677’s GA,ZT content and GA / ABA ratio in pods’ inflated stage, GA and IAA content in pods’ fulling stage, promoted the built of pods’ sink in pods’ inflated stage and the dry matter accumulation rate in pods’ fulling stage,and at least, significantly improved 05D610 and05D677’s pods dry weight, and 05D610’s kernels dry weight.5. Effects of exogenous ABA treatment on endogenous hormone and dry matter accumulation in pods or kernelsExogenous ABA treatment on young pods, throw significantly improving 05D677’s ABA content in pods’ inflated stage and fulling stage, decreasing GA congtent and GA/ABA rate in pods’ inflated stage, promoted the dry matter accumulation rate of pods and kernels in pods’ inflated stage,and at least, significantly improved 05D610 and 05D677’s kernels dry weight, and 05D677’s pods dry weight.