甜瓜掌状裂叶p基因对贮藏期果实后熟生理的调控作用

Regulatory effect of the palmate-lobed leaf gene pll on the post-harvest physiology of melon fruits during storage

ZHANG Qiang1， YONG Liangmin1， DAI Wenting²， SHI Yunjiao¹

（1.Hinanlsfse

al Sciences，Haikou 571100，China）

Abstract： The melon palmate-lobed leaf gene pll belongs to AINTEGUMENTA（ANT） transcription factor gene， which playsan importantrole inregulating plant growthand fruit development.During theresearch，the gene silencing of pll was detected byvirus-induced gene silencing（VIGS）technique.Thechanges of lipoxygenase activity，ethylene release and respiratory metabolism in fruits under normal and silent expression of _pll gene were compared，and the effects of pl （204号 gene silencing inhibitiononthe expression of ethylene synthesisand sugar metabolism enzyme-encoding genes and related enzyme activities in fruitswere studied.The results showed that the low expression of pll gene in fruits could reduce the activityof lipoxygenase，ethylene release and respiration rate.Moreover，the pll gene had a positive regulation efect on ethylene synthesis and carbohydrate metabolism gene expression in fruits，and when the expression of pll gene was suppressed by silencing，the expresion of genes related to ethylene synthesisand glucose metabolism in fruits was also dow-regulated， thus reducing the activities of ethylene synthesis and glucose metabolism enzymes.It can be seen that the pll gene is in

收稿日期：2024-10-29

volvedintheregulationofpost-harvestphysiology，andthe down-regulation of pll gene expression has a delayed and inhibitory effect on the post-harvest physiological metabolismof melon fruits.

Key words：muskmelon； pll gene； gene silen-cing；enzymeactivity；post-harvest physiology

甜瓜（CucumismeloL.）主要产于中国西部地区，其农艺性状优良，果型匀称，口感与风味俱佳，深受消费者喜爱。普通甜瓜的叶片近似圆状心形，叶缘无裂刻。新疆大学国家瓜类工程技术研究中心研究团队在试验田中发现了与伽师系列甜瓜亲缘关系较近的天然突变体，其叶缘有很深的裂刻，总体呈掌状裂型叶，属叶型突变的特异种质，该研究团队将该裂叶突变体命名为 bm7 。Gao 等1对突变体 bm7 进行深入研究，并确定了调控甜瓜掌状裂叶性状的主效基因，该基因被命名为 _pll ，该基因属于珠被发育异常蛋白（ANT）转录因子基因，ANT是一类特殊的植物转录因子，对植株的茎、叶、果实等器官的生长发育有重要的调控作用[2-3]

果实的后熟生理主要涉及乙烯的生物合成、脂肪酸代谢及糖代谢等。脂氧合酶（LOX）是一类含有非血红素铁蛋白的脂肪氧化酶，具有结构特异性[4-5]。在植物生长发育、乙烯生物合成及果实成熟与衰老等一系列生理代谢过程中，脂氧合酶均是不可缺少的物质[。有研究发现， LOX 的代谢产物能够启动果实的乙烯代谢，促进果实成熟[7]。甜瓜属于呼吸跃变型果实，乙烯对果实的后熟起着至关重要的作用。1-氨基环丙烷-1-羧酸（ACC）合成酶编码基因（ACSI）、ACC氧化酶编码基因（ACO1）是重要的乙烯合成相关基因，乙烯合成相关基因和乙烯受体相关基因的表达与果实后熟生理密切相关[8]糖代谢是果实中另一个重要的后熟生理过程[]淀粉与可溶性糖之间的转化是造成果实硬度……