采用营养液栽培,以白籽南瓜（Cucurbita maxima×Cucurbita moschata）为砧木,＂津优3号＂黄瓜为接穗,研究了白籽南瓜嫁接对等渗Ca（NO3）2和NaCl胁迫下黄瓜幼苗生长、氮代谢、渗透调节物质和蛋白表达的影响。结果表明,白籽南瓜嫁接黄瓜可明显促进Ca（NO3）2和NaCl胁迫下黄瓜嫁接苗生长,提高叶片和根系中硝酸还原酶（NR）活性及NO3--N、可溶性糖、脯氨酸和可溶性蛋白含量,抑制NH4＋-N升高;叶片中可溶性蛋白表达量增强,其相对分子质量（×103）分别约为188.4、156.1、120.4、54.0、37.3、32.1、30.6、18.9、17.8和17.1,并出现相对分子质量为64.3×103的一种新蛋白,而81.0×103的蛋白表达量减弱,这12种蛋白可能与白籽南瓜嫁接提高黄瓜耐盐性密切相关。研究还发现,NaCl胁迫下黄瓜自根嫁接和砧木嫁接植株叶片中相对分子质量（×103）约为86.1、23.4、18.9和17.8的蛋白表达量大于等渗的Ca（NO3）2,相对分子质量（×103）约为188.4、156.1、54.0和17.1的蛋白表达量小于等渗的Ca（NO3）2;NaCl胁迫9 d后39.1×103、35.4×103和21.2×103三种蛋白在自根嫁接株中消失,这11种蛋白可能与白籽南瓜嫁接株耐Ca（NO3）2胁迫能力强有关。综上,Ca（NO3）2胁迫对黄瓜幼苗造成的伤害程度显著低于等渗的NaCl胁迫,白籽南瓜砧木嫁接可调节黄瓜植株体内氮素代谢,提高渗调能力,有效地缓解Ca（NO3）2和NaCl胁迫对黄瓜植株的伤害,尤其对Ca（NO3）2胁迫伤害的缓解效果明显,可以作为黄瓜耐盐砧木在生产上应用。%expression cucumber Effects of grafting on the growth, nitrogen metabolism, osmoregulatory substances and soluble protein was conducted with pumpkin （ Cucurbita maxima × Cucurbita moschata） as the rootstock and a cultivar ＇Jinyou No. 3＇ as the scion under iso-osmotic Ca （NO3 ）2 or NaC1 stress. Results showed that the rootstock-grafted seedlings significantly enhanced the growth, NR activity, NO3--N, soluble protein, soluble sugar, proline content and decreased NH＋4-N content under iso-osmotic Ca（ NO3 ）2 and NaC1 stress. SDS -PAGE profilesshowed that there were twelve differentially-expressed proteins in leaves of rootstock-grafted seedlings in present of salt treatment. Of these twelve proteins, ten proteins were up-regulated including the proteins of relative molecular weight （ ×10^3） for 188.4, 156. 1, 120. 4, 54. 0, 37.3, 32. 1, 30. 6, 18. 9, 17. 8 and 17. 1, while one proteins of 81.0× 10^3 were down-regulated and turned a novel protein of 63.4 x 103. And then, these twelve proteins were probably related to enhancement of salt-tolerance of rootstock-grafted cucumber seedlings. Results a/so showed theexpressing of four proteins of relative molecular weight （ ×10^3 ） such as 86. 1,23.4, 18. 9 and 17.8 were stronger in both self-grafted and rootstock-grafted seedlings under NaC1 stress than that under Ca （NO3）2 stress, whereas the expressing of proteins relative molecular weight （×10^3 ） such as 188. 4, 156. l, 54. 0 and 17. 1 were lower under NaC1 stress than that under Ca （NO3）2 stress. And three proteins disappeared in self-grafted seedlings under NaCl stress for 9 days related to the high tolerance to Ca（ NO3 ）2 stress of rootstock-grafted of 39. 1 ×10^3, 35.4×10^3 and 21.2×10^3 even It was possible that these eleven proteins were cucumber seedlings. In conclusion, the damages caused by NaC1 stress were more serious than that by Ca （ NO3 ）2 stress, and rootstock-grafting could effectively alleviated the injury by regulating nitrogen metabolism and osmoregulatory substances of cucumber seedlings under salt stress. It seemed that the alleriating effect in rootstock-grafted plants more expressing under Ca（ NO3 ）2 stress.
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